Determining the integrity of a computing device

Information

  • Patent Grant
  • 10884059
  • Patent Number
    10,884,059
  • Date Filed
    Wednesday, October 18, 2017
    6 years ago
  • Date Issued
    Tuesday, January 5, 2021
    3 years ago
Abstract
Systems and methods for determining the integrity of metrology systems are provided. A method according to one implementation includes the step of storing, with a computer having a system clock, an initialization time at which a device is connected to the computer. The method also includes receiving, with the computer, information obtained by the device and associating an electronic timestamp to the information. The electronic timestamp is based on the system clock when the computer receives the information obtained by the device. The method also includes counting clock cycles to determine an elapsed time from the initialization time to the time when the computer receives the information obtained by the device. Also, the method determines if the system clock has been altered by comparing the electronic timestamp to the sum of the initialization time and the elapsed time.
Description
FIELD OF THE INVENTION

The present invention relates to certifying metrology systems and more particularly relates to determining the integrity of computing devices used in metrology systems.


BACKGROUND

Commerce in the United States and other civilized countries relies heavily on the accuracy and integrity of measurement devices. Various measurement devices may include, for example, devices for measuring weight, volume, length, count, and/or other various parameters. In the United States, approximately half of all sales are influenced in some respects by weights and measures regulations. In order for a commercial system to operate effectively and for a satisfactory level of confidence to be provided to buyers and sellers, laws and regulations must be put into place.


Therefore, measurement devices are required to meet certain standards and specifications regarding weights and measures certification. Clearly, one of the goals of measurement regulations is to prevent unethical or deceptive practices.


One common requirement regarding certification is that metrology devices are to maintain a log of measurements that are taken. Also, another requirement may be that electronic timestamps, which include the dates and times when the measurements were obtained, are to be recorded.


Some metrology devices may be stand-alone devices or “built-for-purpose” devices, which may be configured with components for measuring and logging the measurement data. These stand-alone metrology devices may be checked to determine if they meet applicable weights and measures certification, which may include the integrity of the timestamp process.


However, in some environments, a measuring device may be used in conjunction with another device, such as a computer, which may not be required to include the same level of integrity with respect to weights and measures. In these situations, a measuring device certified to meet certain specification may be matched with another device that may be used in an unethical or illegal manner to evade those specifications.


For example, a dimensioner may be used for measuring the dimensions of a package for shipping. The dimensioner may be certified to accurately determine the dimensions of the package to calculate a volume on which shipping costs may be based. However, this dimensioner may be connected with a general-purpose computer, which may be used for storing measurement data and for recording a timestamp indicative of the time and date when the measurement was obtained. If the system clock of the computer is altered, the timestamp information may become unreliable, thereby tainting the overall integrity of the measurement system. Changes to the system clock may be caused inadvertently, but, in other cases, may be caused by fraudulent practices.


Therefore, a need exists for monitoring the system clock of a computer, especially a computer that is incorporated in a measurement system or a computer running software with a time-dependent user license. By monitoring the system clock of the computer, certain deceptive activities can be caught, and buyers and sellers can be assured that ethical commercial practices are being followed.


SUMMARY

Accordingly, the present invention embraces systems and methods for monitoring the integrity of a metrology system. In particular, the system clock of a computer may be analyzed to determine if the clock has been altered.


In an exemplary embodiment, a method for determining whether a system clock has been altered comprises the step of storing, with a computer comprising a system clock, an initialization time at which a device is connected to the computer. The initialization time is based on the system clock. The method also includes receiving, with the computer, information obtained by the device and associating an electronic timestamp to the information. The electronic timestamp is based on the system clock when the computer receives the information obtained by the device. The method also includes counting clock cycles to determine an elapsed time from the initialization time to the time when the computer receives the information obtained by the device. Also, the method includes determining if the system clock has been altered by comparing the electronic timestamp to the sum of the initialization time and the elapsed time.


In another exemplary embodiment, a method comprises the step of monitoring a system time of a general-purpose computer, wherein a system clock of the general-purpose computer is configured to provide the system time. The method also includes utilizing a counter of the general-purpose computer to determine an elapsed time. Also, the method includes employing the system time and elapsed time to determine if the system clock has been altered.


In another exemplary embodiment, a non-transitory computer readable medium for storing a timestamp verifying program is provided. The non-transitory computer readable medium allows a computer to verify an electronic timestamp. The non-transitory computer readable medium is configured to allow the computer to monitor a system time provided by a system clock of a computer and count clock cycles to determine an elapsed time. Furthermore, the non-transitory computer readable medium is configured to allow the computer to employ the system time and elapsed time to determine if the system clock has been altered.


In yet another exemplary embodiment, a system is provided. The system comprises a certified device configured to obtain information related to a plurality of events. The system also includes a general-purpose computer connected to the certified device. The general-purpose computer includes a system clock for providing a system time, a time monitoring module for monitoring the system time, and a counting device for counting clock cycles to determine an elapsed time. The general-purpose computer is configured to apply an electronic timestamp to each of the plurality of events. The time monitoring module is configured to employ the system time and elapsed time to determine if the system clock has been altered.


The foregoing illustrative summary, as well as other exemplary objectives and/or advantages of the invention, and the manner in which the same are accomplished, are further explained within the following detailed description and its accompanying drawings.





BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 schematically depicts a block diagram of a stand-alone metrology device, according to an embodiment of the present invention.



FIG. 2 schematically depicts a block diagram of a metrology system, according to an embodiment of the present invention.



FIG. 3 schematically depicts a block diagram of a dimensioning device, according to an embodiment of the present invention.



FIG. 4 schematically depicts a block diagram of the general-purpose computer shown in FIG. 2, according to an embodiment of the present invention.



FIG. 5 schematically depicts a flow diagram of a first method for detecting discrepancies in the system time, according to one embodiment of the present invention.



FIG. 6 schematically depicts a flow diagram of a second method for detecting discrepancies in the system time, according to another embodiment of the present invention.



FIG. 7 schematically depicts a flow diagram of a third method for detecting discrepancies in the system time, according to yet another embodiment of the present invention.





DETAILED DESCRIPTION

The present invention embraces systems that include a certified metrology device and an off-the-shelf device, such as a computer. The off-the-shelf device may not necessarily require the same measurement certification as the metrology device with which it operates. Unfortunately, such an unequal pairing can lead to practices that can compromise the integrity of the system. For example, some metrology devices may allow the off-the-shelf device to couple a timestamp with the measurement data. However, if the system clock of the off-the-shelf device is altered, the timestamp will not be reliable.


The present invention is further directed to systems and methods for monitoring a system clock of a computer. By detecting an alteration in the system clock of the computer, the present invention can catch a perpetrator in the act by collecting evidence of unethical alterations. From this point, the evidence of system clock alterations may be used to incriminate the perpetrator.


A software program for performing the system clock analysis can be loaded into the computer to be monitored. The program may be downloaded from a website, installed from an external storage unit, transferred from the metrology device itself, or using other suitable means. By using a software program to perform the system clock analysis, any added costs or design changes to the metrology device can be alleviated.



FIG. 1 is a block diagram illustrating an embodiment of a metrology device 2 that may be used in a stand-alone manner. The stand-alone metrology device 2 in this example includes at least a measuring module 4, a time module 6, computing hardware 8, an operating system 10, and a data/time log 12. The measuring module 4 may include any number or combination of components for measuring any measurable parameter. The time module 6 may include a clock or other type of timer or counter for determining a date and time when the measurements are taken by the measurement module 4. The time module 6 may further be configured to monitor the clock of the stand-alone metrology device 2. For example, the time module may perform an analysis to determine if the clock is changed to verify that the timestamps are valid.


The measurements and electronic timestamp information may be stored in the data/time log 12. The computing hardware 8 and operating system 10 may include any number or combination of suitable components, such as digital signal processors, central processing units, microprocessors, etc. for controlling the operations of the stand-alone metrology device 2.



FIG. 2 is a block diagram showing an embodiment of a metrology system 14, which, in this embodiment, includes a metrology device 16 and a general-purpose computer 18. According to this embodiment, the metrology device 16 may not include the same time module 6, computing hardware 8, and operating system 10 as is incorporated in the stand-along metrology device 2 of FIG. 1. Instead, the metrology device 16 shown in FIG. 2 may require the use of the general-purpose computer 18 for performing some of the processing tasks, particularly the application of timestamps.


The general-purpose computer 18 may be a personal computer, a not-built-for-purpose computer, laptop, tablet, smart phone, or other suitable computing device. According to some embodiments, the general-purpose computer 18 may be connected to the metrology device 16, but isolated from any other external communication networks or devices.


The metrology system 14 may include a typical arrangement for many types of metrology devices that may be unable to operate without additional processing power. For example, the metrology device 16 may be a dimensioning device for detecting the volume of an object. When measurements are made, the measurement data may be transmitted to the general-purpose computer 18 for storing the data and for recording timestamps.


Therefore, in operation, the metrology device 16 may be configured to measure one or more parameters, such as weight, volume, length, etc. In some embodiments, the general-purpose computer 18 may first provide an instruction to the metrology device 16 to make these measurements.


The measured parameters may then be stored in the metrology device 16 itself and/or the metrology device 16 may transmit the parameters to the general-purpose computer 18 for storage. The general-purpose computer 18 may be configured to store the data in a suitable memory device. Along with the measurement data, the general-purpose computer 18 may also be configured to store an electronic timestamp. The electronic timestamp may include date and time information using any suitable time format. According to some measurement environments, the day and time information may be important for determining if expiration dates/times have been reached, for calculating shipping costs based on time, and for other reasons.


Therefore, it may be necessary to ensure that hackers or unethical users have not changed the system clock on the general-purpose computer 18 and thereby tampered with the entry of the electronic timestamps. In these types of measurement environments, the integrity of the metrology logging system 14 relies on the accuracy of the timestamps being applied to the measurements.



FIG. 3 is a block diagram showing an embodiment of a dimensioning device 20 or multi-dimensional measuring device (MDMD). The dimensioning device 20 may be one of multiple types of metrology devices represented by the metrology device 16 shown in FIG. 2 that may be connected to an external device (e.g., computer). In this embodiment of FIG. 3, the dimensioning device 20 includes one or more lenses 22, one or more sensors 24, and a processing device 26. According to one implementation, the dimensioning device 20 may be configured to detect the dimensions of an object 28, such as a box or package.



FIG. 4 is a block diagram showing an embodiment of the general-purpose computer 18 shown in FIG. 1. According to the embodiment of FIG. 4, the computer 18 includes a processor 32, a system clock 34, a memory 36, a communication device 38, and input/output devices 40, among other components. The processor 32, system clock 34, memory 36, communication device 38, and input/output devices 40 may communicate with each one another via a bus interface 42.


As illustrated in FIG. 4, the processor 32 may include a counter 44 or other time tracking device for measuring processing cycles, which may be an integer multiple of the cycles of the system clock 34. The system clock 34 may include an oscillator 46, such as a crystal oscillator, for generating a system frequency from which the operating frequencies of various components of the computer 18 may be derived.


Furthermore, the memory 36 of the general-purpose computer 18 may be configured to store data and software in volatile and non-volatile memory components. For example, the memory 36 may include a time monitoring module 48, which may be configured according to the embodiments of the present invention to detect tampering with the system clock 34.


The memory 36 may also include a data log 50 for storing measurement data obtained from the associated metrology device. The memory may also include a time log 52, which may be configured to store timestamp information. Also, the time log 52 may be configured to store events related to detected discrepancies in the timestamps and/or system clock 34. The stored events in the time log 52 may be indicative of tampering events or other events detected by the time monitoring module 48 in which the integrity of the metrology system 14 has been compromised.


The communication device 38 may be configured to communicate with the metrology device 16 when the general-purpose computer 18 is connected in the arrangement shown in FIG. 2. The communication device 38 may send instructions to the metrology device 16 requesting that the metrology device 16 perform a measurement function. Also, the communication device 38 may receive measurement data from the metrology device 16.


According to various embodiments, the communication device 38 may include wired components for connecting the general-purpose computer 18 to the metrology device 16 and/or may include wireless components for allowing the computer 18 and metrology device 16 to communicate wirelessly. For example, wireless communication may include Bluetooth, Wi-Fi, near field communication (NFC), or other suitable wireless protocols.


The input/output devices 40 of the general-purpose computer 18 may include input elements, such as keyboards, keypads, barcode scanners, touch screen devices for receiving user input, microphones, mouse components, and/or other suitable user input elements. Also, the input/output devices 40 may include output elements, such as displays, monitors, speakers, buzzers, tactile output devices, and/or other suitable user output elements.


In some embodiments, the time monitoring module 48 may be configured to operate in conjunction with time-dependent software licenses. For example, if a software license allows a user to use one or more software programs for a predetermined amount of time (e.g., one month), the time monitoring module 48 may be configured to verify that the system clock 34 has not been modified during the duration of the license.


Additionally, the system integrity operations of the present invention may be helpful if a computer is hacked and the hacker attempts to cover his/her tracks by changing the system time of the system clock 34. The present invention is capable of capturing events regarding the system time change, which may be used to detect the hacker. For example, the system integrity operations may be able to catch a hacker who might be able to trick a user into sharing information with a false server that has a different time. The present invention may also be used during a denial or service attack or when a system time is changed to make a certificate validation failure. The present invention can detect and report the issue along with the actual time when the attack was made.


According to the embodiments of the present invention, the time module 6 of the stand-alone metrology device 2 of FIG. 1 and/or the time monitoring module 48 of the general-purpose computer 18 used in the metrology system 14 of FIG. 2 may be configured to monitor the integrity of the respective systems. By monitoring time characteristics, the modules 6 and 48 can detect when a system clock has been altered within their respective systems. Therefore, the time monitoring functions may be used to detect whether the devices within the metrology systems can reliably apply a proper timestamp to measurement data.


The methods described below with respect to FIGS. 5-7 are embodiments of the operations and functionality of the time module 6 and/or time monitoring module 48. It should be noted that other methods may be used to monitor timestamp information to determine if a system clock has been modified during use of a metrology system. The time module 6 and time monitoring module 48 are configured to record events that may be indicative of tampering with the system clock. In some embodiments, the recorded discrepancies and other event information may be stored and protected with encryption.


The embodiments of the present invention may be applicable to metrology systems that are not necessarily connected to an external network, such as a wide-area network (WAN) or the Internet. Instead, the metrology systems may be stand-alone systems and may be configured to detect the integrity of timestamp processes independently of external devices or systems.


However, according to some embodiments, the metrology systems described herein may be connected to external networks to allow additional monitoring of timestamp information. For example, timestamp information may be verified by using an Internet connection, a cellular link, a global positioning system (GPS) reading, or other network-dependent means. Nevertheless, as mentioned above, the time module 6 and time monitoring module 48 may operate independently of the external networks and system, which may thereby simplify the methods and alleviate the need for extensive hardware changes or other costs.


The methods of FIGS. 5-7 may be executed by the time module 6 and/or time monitoring module 48 to assess whether the data log is accurate. The functions of the methods of FIGS. 5-7 may be configured as logic in one or more software programs executed by a suitable processing device. In other embodiments, the functions may be configured in hardware. In some embodiments, software and/or firmware components may be uploaded from the metrology device 16 to the general-purpose computer 18 or downloaded from a network device via a suitable network.



FIG. 5 is a flow diagram showing an embodiment of a first method 60 for detecting discrepancies in the system time. In some implementations, the method 60 may include a first step of initializing a program to open a protected data log, to capture the current system date/time, and to write the data/time information to a log. As shown, the method 60 includes capturing an initial system time, as indicated in block 62. A counter is sampled to obtain an initial count value, as indicated in block 64. The counter may be a microprocessor cycle counter, which may be internal to the computer, for providing a running count of the number of milliseconds since the computer was turned on.


The method 60 also includes the process of waiting for an event (e.g., measurement) to be logged, as indicated in decision diamond 66. If it is determined in decision diamond that there are no events to be logged, then the method 60 repeats the step until a measurement or other event has occurred. When a measurement is obtained or when an event occurs, the method 60 proceeds to block 68.


According to block 68, the method 60 includes logging the measurement or event. As indicated in block 70, the current system time is captured. From the initial system time captured with respect to block 62 and the current system time captured with respect to block 70, a difference in the system time is calculated, as indicated in block 72.


Also, the counter is sampled again, as indicated in block 74, to obtain an end count value. From the initial count value obtained with respect to block 64 and the end count value obtained with respect to block 74, a difference in the count values is calculated to determine elapsed time, as indicated in block 76. The method 60 also includes the step of comparing the system time difference (calculated in block 72) with the elapsed time (calculated in block 76). The comparison of block 78 may include subtracting the two values to determine a difference.


As indicated in decision diamond 80, the method 60 includes the step of determining if the difference (based on the comparison of block 78) exceeds a predetermined threshold. In some embodiments, the predetermined threshold may be set to any minimum level, such as 10 seconds or 20 seconds. If there is a mismatch, or, in other words, if the difference between system time difference and the elapsed time exceeds the predetermined threshold, then the method 60 proceeds from decision diamond 80 to block 82. As indicated in block 82, the discrepancy is recorded. The time that the discrepancy was detected along with other pertinent information may be stored.


If it is determined in decision diamond 80 that the difference does not exceed the threshold, the method 60 may proceed to block 84 and the process repeated. In some embodiments, the method 60 may come to an end at this point if no more events are to be monitored. As indicated in block 84, the current system time that was captured with respect to block 70 is used as an initial time for the next event. Also, the end count value obtained with respect to block 74 is used as an initial count value for the next event. After converting the current values to initial values for use with the next event, the method 60 loops back from block 84 to decision diamond 66 to wait for the next event and the process can be repeated indefinitely.


In order to test the method and verify that changes to the system clock can be reliably captured, a software program may be used. An example of a C# program that compiles using Visual Studio is included below:

















public partial class Form1 : Form



{



   private int timerCurrentValue = 100;



   private int referenceTickCount = 0;



   private DateTime referenceDateTime;



public Form1( )



{



   InitializeComponent( );



   referenceTickCount = System.Environment.TickCount;



   referenceDateTime = DateTime.Now;



}



private void LogString( string textToLog )



{



const Int64 msecTimeChangeThreshold = 500;



DateTime currentDateTime = DateTime.Now;



Int64 currentTickCount = System.Environment.TickCount;



Int64 deltaTicksSinceReference = currentTickCount −



   referenceTickCount;



Int64 deltaDateTime = currentDateTime.ToBinary( ) −



   referenceDateTime.ToBinary( );



tbTickCount.Text = currentTickCount.ToString( );



DateTime logDateTime = DateTime.FromBinary(deltaDateTime);



string logString = currentDateTime.ToString( ) + “ “ +



   textToLog + “ dTicks(ms): “ + deltaTicksSinceReference” +



   dTime(min:sec.ms): “ +



   logDateTime.Minute.ToString(“D2”) + “:” +



   logDateTime.Second.ToString(“D2”) + “.” +



   logDateTime.Millisecond.ToString(“D3”) + “\r\n” ;



Int64 msecSinceReference = (logDateTime.Minute * 60 * 1000) +



   (logDateTime.Second * 1000) + logDateTime.Millisecond;



Int64 diffTimeMethods = Math.Abs(deltaTicksSinceReference −



   msecSinceReference);



   if (diffTimeMethods < msecTimeChangeThreshold)



   {



   tbLog.SelectionColor = System.Drawing.Color.Black;



   }



   else



   {



   tbLog.SelectionColor = System.Drawing.Color.Red;



   referenceTickCount = System.Environment.TickCount;



   referenceDateTime = DateTime.Now



   }



tbLog.AppendText(logString);



}



}











FIG. 6 is a flow diagram showing another embodiment of a method 90 for detecting discrepancies in the system time. In some implementations, the method 90 may be executed in place of method 60 of FIG. 5 or may be executed in parallel with method 60. As shown in FIG. 6, method 90 includes a first step of starting a loop, as indicated in block 92. The loop may be configured to endure for a certain amount of time (e.g., ten seconds). As indicated in block 94, an initial system time is captured. The method 90 also includes waiting for the end of the loop. As indicated in decision block 96, it is determined whether or not the loop has reached its end. If not, the decision block 96 is repeated until the end is reached, at which point, the method proceeds to block 98.


As indicated in block 98, an end-of-loop system time is captured. A difference between the end-of-loop system time (captured with respect to block 98) and the initial system time (captured with respect to block 94) is calculated, as indicated in block 100. This difference value is then stored, as indicated in block 102.


The method 90 also include a decision diamond 104, which determines whether the difference value (calculated with respect to block 100) is the same as other stored difference values that may have been calculated and stored during previous loops having the same time periods (e.g., ten seconds). If the values are the same, then no issues are detected, and the method 90 loops back to block 92 to repeat the process for the next loop. This process may be repeated indefinitely or until it is determined that a discrepancy is detected. If a discrepancy is detected in decision diamond 104, the method 90 proceeds to block 106, which indicates that the discrepancy is recorded.


The loop may be repeated over and over and the initial loop value may be compared with end loop value. This difference should be constant at the end of each loop. However, if the system clock is adjusted, the loop is compromised and will give a different value. The results of the test can be written to a log, such as log 12 (FIG. 1), data log 50 (FIG. 4), or time log 52 (FIG. 4).


In order to test the method 90 and verify that changes to the system clock can be reliably captured, a software program may be used. An example of a Basic language program is included below:

















REM Timecatcher Program for catching a change in system time



OPEN “timecatch.txt” FOR OUTPUT AS #1 ‘creates log



NoCatch = 0 ‘log write flag



PRINT #1, “Timecatcher log start time is “; TIME$



TIMER ON



stp = TIMER



FOR a = 1 TO 4 ‘ten second loops



   strt = TIMER



   DO UNTIL stp − strt > 10 OR stp − strt < 0 ‘difference of



      seconds or negative when tampered with



      stp = TIMER



   LOOP



   dif = stp − strt



   t$ = TIME$



   IF INT(dif) <> 10 THEN PRINT #1, “Computer operating



system time changed at “; oldt$: NoCatch = 1



   oldt$ = t$



NEXT a



PRINT #1, “Timecatcher log stop time is “; TIME$



IF NoCatch = 0 THEN PRINT #1, “Computer operating system time



was not tampered with or adjusted during this interval.”



CLOSE #1



END











FIG. 7 is a flow diagram showing an embodiment of a third method 110 for detecting discrepancies in the system time. According to this method 110, a data log is analyzed, as indicated in block 112, for determining if timestamps are sequential. As indicated in block 114, the timestamp of a present event (or subsequent event) is compared with the timestamp of an event that immediately precedes the present event.


It should be clear that the next event should have a timestamp that indicates a later time than the earlier event. The decision diamond 116 indicates that the comparison of block 114 is analyzed to determine if the next event has a timestamp that has been marked with an earlier time. If such an out-of-sequence event is detected, the method 110 includes proceeding to block 118, which indicates that the discrepancy is recorded. Otherwise, if the event is recorded with a timestamp that properly follows the earlier event, then the method may proceed to decision diamond 120, which determines whether more events are to be analyzed. If so, the method 110 loops back to block 114 to repeat the analysis of the data log. Otherwise, the method 110 may come to an end.


It is beneficial to maintain the integrity of the data log. In some cases, it may be even more important to detect when the time on a computer is moved back since subsequent fraudulent measurements may replace an actual measurement taken at the same system time. The method of FIG. 7 is therefore a simple process for detecting when the system clock has been moved to an earlier time.


The method of FIG. 7 can detect a negative time change. Also, the method does not necessarily need to run during the capturing of events. A data log can be analyzed after the fact to determine if any timestamps are out of sequence. When a subsequent timestamp is determined to have an earlier system time, then an error is detected.


The methods of FIGS. 5-7 and other suitable methods may be used to catch a hacker in the act of changing a system time. By recording information related to the time change, further action can be taken to catch the hackers, nefarious users of time-limited software licenses, or other culprits responsible for changing the time.


In steps 82, 106, and 118 of the respective methods, when the discrepancy is recorded, the method may further be configured to lock the metrology device or computer so that no further actions can be taken until the issues are resolved. In some cases, freezing the metrology device or computer may be required in response to detecting the discrepancy, as regulated by various jurisdictions. A message may be displayed on an output device 40 to communicate to the user that the metrology device cannot be used until it is checked by an inspector.


Similarly, the metrology systems with detected discrepancies may be programmed to require a manager to “sign-off” in order to continue operation. A report may be sent to local authorities explaining the discrepancy, such as via email. The report may be accessed when the metrology device is scheduled for a regular field test. An inspector may be able to review the report and determine if additional discrepancies have been repeated. It may be necessary in some cases to use the recorded information of the time discrepancy in a criminal proceeding.


In some embodiments, the recording of the discrepancy (e.g., blocks 82, 106, 118) may not include additional actions other than the simple storing of the time-discrepancy event information. However, if a customer complaint is received regarding the particular metrology device, an inspector can check the log to see if any time-discrepancy events have been recorded.


The systems and methods described herein may be considered as a simple solution for detecting discrepancies in the system clock of a general-purpose computer or in a programmable stand-alone metrology device. The systems and methods may be used in jurisdictions that require a Certificate of Conformance for measurement systems. Otherwise, tampered systems might result in charging customers incorrect amounts.


To supplement the present disclosure, this application incorporates entirely by reference the following commonly assigned patents, patent application publications, and patent applications:

  • U.S. Pat. Nos. 6,832,725; 7,128,266; 7,159,783; 7,413,127; 7,726,575; 8,294,969; 8,317,105; 8,322,622; 8,366,005; 8,371,507; 8,376,233; 8,381,979; 8,390,909; 8,408,464; 8,408,468; 8,408,469; 8,424,768; 8,448,863; 8,457,013; 8,459,557; 8,469,272; 8,474,712; 8,479,992; 8,490,877; 8,517,271; 8,523,076; 8,528,818; 8,544,737; 8,548,242; 8,548,420; 8,550,335; 8,550,354; 8,550,357; 8,556,174; 8,556,176; 8,556,177; 8,559,767; 8,599,957; 8,561,895; 8,561,903; 8,561,905; 8,565,107; 8,571,307; 8,579,200; 8,583,924; 8,584,945; 8,587,595; 8,587,697; 8,588,869; 8,590,789; 8,596,539; 8,596,542; 8,596,543; 8,599,271; 8,599,957; 8,600,158; 8,600,167; 8,602,309; 8,608,053; 8,608,071; 8,611,309; 8,615,487; 8,616,454; 8,621,123; 8,622,303; 8,628,013; 8,628,015; 8,628,016; 8,629,926; 8,630,491; 8,635,309; 8,636,200; 8,636,212; 8,636,215; 8,636,224; 8,638,806; 8,640,958; 8,640,960; 8,643,717; 8,646,692; 8,646,694; 8,657,200; 8,659,397; 8,668,149; 8,678,285; 8,678,286; 8,682,077; 8,687,282; 8,692,927; 8,695,880; 8,698,949; 8,717,494; 8,717,494; 8,720,783; 8,723,804; 8,723,904; 8,727,223; 8,740,082; 8,740,085; 8,746,563; 8,750,445; 8,752,766; 8,756,059; 8,757,495; 8,760,563; 8,763,909; 8,777,108; 8,777,109; 8,779,898; 8,781,520; 8,783,573; 8,789,757; 8,789,758; 8,789,759; 8,794,520; 8,794,522; 8,794,525; 8,794,526; 8,798,367; 8,807,431; 8,807,432; 8,820,630; 8,822,848; 8,824,692; 8,824,696; 8,842,849; 8,844,822; 8,844,823; 8,849,019; 8,851,383; 8,854,633; 8,866,963; 8,868,421; 8,868,519; 8,868,802; 8,868,803; 8,870,074; 8,879,639; 8,880,426; 8,881,983; 8,881,987; 8,903,172; 8,908,995; 8,910,870; 8,910,875; 8,914,290; 8,914,788; 8,915,439; 8,915,444; 8,916,789; 8,918,250; 8,918,564; 8,925,818; 8,939,374; 8,942,480; 8,944,313; 8,944,327; 8,944,332; 8,950,678; 8,967,468; 8,971,346; 8,976,030; 8,976,368; 8,978,981; 8,978,983; 8,978,984; 8,985,456; 8,985,457; 8,985,459; 8,985,461; 8,988,578; 8,988,590; 8,991,704; 8,996,194; 8,996,384; 9,002,641; 9,007,368; 9,010,641; 9,015,513; 9,016,576; 9,022,288; 9,030,964; 9,033,240; 9,033,242; 9,036,054; 9,037,344; 9,038,911; 9,038,915; 9,047,098; 9,047,359; 9,047,420; 9,047,525; 9,047,531; 9,053,055; 9,053,378; 9,053,380; 9,058,526; 9,064,165; 9,064,165; 9,064,167; 9,064,168; 9,064,254; 9,066,032; 9,070,032; 9,076,459; 9,079,423; 9,080,856; 9,082,023; 9,082,031; 9,084,032; 9,087,250; 9,092,681; 9,092,682; 9,092,683; 9,093,141; 9,098,763; 9,104,929; 9,104,934; 9,107,484; 9,111,159; 9,111,166; 9,135,483; 9,137,009; 9,141,839; 9,147,096; 9,148,474; 9,158,000; 9,158,340; 9,158,953; 9,159,059; 9,165,174; 9,171,543; 9,183,425; 9,189,669; 9,195,844; 9,202,458; 9,208,366; 9,208,367; 9,219,836; 9,224,024; 9,224,027; 9,230,140; 9,235,553; 9,239,950; 9,245,492; 9,248,640; 9,250,652; 9,250,712; 9,251,411; 9,258,033; 9,262,633; 9,262,660; 9,262,662; 9,269,036; 9,270,782; 9,274,812; 9,275,388; 9,277,668; 9,280,693; 9,286,496; 9,298,964; 9,301,427; 9,313,377; 9,317,037; 9,319,548; 9,342,723; 9,361,882; 9,365,381; 9,373,018; 9,375,945; 9,378,403; 9,383,848; 9,384,374; 9,390,304; 9,390,596; 9,411,386; 9,412,242; 9,418,269; 9,418,270; 9,465,967; 9,423,318; 9,424,454; 9,436,860; 9,443,123; 9,443,222; 9,454,689; 9,464,885; 9,465,967; 9,478,983; 9,481,186; 9,487,113; 9,488,986; 9,489,782; 9,490,540; 9,491,729; 9,497,092; 9,507,974; 9,519,814; 9,521,331; 9,530,038; 9,572,901; 9,558,386; 9,606,581; 9,646,189; 9,646,191; 9,652,648; 9,652,653; 9,656,487; 9,659,198; 9,680,282; 9,697,401; 9,701,140;
  • U.S. Design Pat. Nos. D702,237; D716,285; D723,560; D730,357; D730,901; D730,902; D734,339; D737,321; D754,205; D754,206; D757,009; D760,719; D762,604; D766,244; D777,166; D771,631; D783,601; D785,617; D785,636; D790,505; D790,546;
  • International Publication No. 2013/163789;
  • U.S. Patent Application Publication No. 2008/0185432; U.S. Patent Application Publication No. 2009/0134221; U.S. Patent Application Publication No. 2010/0177080; U.S. Patent Application Publication No. 2010/0177076; U.S. Patent Application Publication No. 2010/0177707; U.S. Patent Application Publication No. 2010/0177749; U.S. Patent Application Publication No. 2010/0265880; U.S. Patent Application Publication No. 2011/0202554; U.S. Patent Application Publication No. 2012/0111946; U.S. Patent Application Publication No. 2012/0168511; U.S. Patent Application Publication No. 2012/0168512; U.S. Patent Application Publication No. 2012/0193423; U.S. Patent Application Publication No. 2012/0194692; U.S. Patent Application Publication No. 2012/0203647; U.S. Patent Application Publication No. 2012/0223141; U.S. Patent Application Publication No. 2012/0228382; U.S. Patent Application Publication No. 2012/0248188; U.S. Patent Application Publication No. 2013/0043312; U.S. Patent Application Publication No. 2013/0082104; U.S. Patent Application Publication No. 2013/0175341; U.S. Patent Application Publication No. 2013/0175343; U.S. Patent Application Publication No. 2013/0257744; U.S. Patent Application Publication No. 2013/0257759; U.S. Patent Application Publication No. 2013/0270346; U.S. Patent Application Publication No. 2013/0292475; U.S. Patent Application Publication No. 2013/0292477; U.S. Patent Application Publication No. 2013/0293539; U.S. Patent Application Publication No. 2013/0293540; U.S. Patent Application Publication No. 2013/0306728; U.S. Patent Application Publication No. 2013/0306731; U.S. Patent Application Publication No. 2013/0307964; U.S. Patent Application Publication No. 2013/0308625; U.S. Patent Application Publication No. 2013/0313324; U.S. Patent Application Publication No. 2013/0332996; U.S. Patent Application Publication No. 2014/0001267; U.S. Patent Application Publication No. 2014/0025584; U.S. Patent Application Publication No. 2014/0034734; U.S. Patent Application Publication No. 2014/0036848; U.S. Patent Application Publication No. 2014/0039693; U.S. Patent Application Publication No. 2014/0049120; U.S. Patent Application Publication No. 2014/0049635; U.S. Patent Application Publication No. 2014/0061306; U.S. Patent Application Publication No. 2014/0063289; U.S. Patent Application Publication No. 2014/0066136; U.S. Patent Application Publication No. 2014/0067692; U.S. Patent Application Publication No. 2014/0070005; U.S. Patent Application Publication No. 2014/0071840; U.S. Patent Application Publication No. 2014/0074746; U.S. Patent Application Publication No. 2014/0076974; U.S. Patent Application Publication No. 2014/0097249; U.S. Patent Application Publication No. 2014/0098792; U.S. Patent Application Publication No. 2014/0100813; U.S. Patent Application Publication No. 2014/0103115; U.S. Patent Application Publication No. 2014/0104413; U.S. Patent Application Publication No. 2014/0104414; U.S. Patent Application Publication No. 2014/0104416; U.S. Patent Application Publication No. 2014/0106725; U.S. Patent Application Publication No. 2014/0108010; U.S. Patent Application Publication No. 2014/0108402; U.S. Patent Application Publication No. 2014/0110485; U.S. Patent Application Publication No. 2014/0125853; U.S. Patent Application Publication No. 2014/0125999; U.S. Patent Application Publication No. 2014/0129378; U.S. Patent Application Publication No. 2014/0131443; U.S. Patent Application Publication No. 2014/0133379; U.S. Patent Application Publication No. 2014/0136208; U.S. Patent Application Publication No. 2014/0140585; U.S. Patent Application Publication No. 2014/0152882; U.S. Patent Application Publication No. 2014/0158770; U.S. Patent Application Publication No. 2014/0159869; U.S. Patent Application Publication No. 2014/0166759; U.S. Patent Application Publication No. 2014/0168787; U.S. Patent Application Publication No. 2014/0175165; U.S. Patent Application Publication No. 2014/0191684; U.S. Patent Application Publication No. 2014/0191913; U.S. Patent Application Publication No. 2014/0197304; U.S. Patent Application Publication No. 2014/0214631; U.S. Patent Application Publication No. 2014/0217166; U.S. Patent Application Publication No. 2014/0231500; U.S. Patent Application Publication No. 2014/0247315; U.S. Patent Application Publication No. 2014/0263493; U.S. Patent Application Publication No. 2014/0263645; U.S. Patent Application Publication No. 2014/0270196; U.S. Patent Application Publication No. 2014/0270229; U.S. Patent Application Publication No. 2014/0278387; U.S. Patent Application Publication No. 2014/0288933; U.S. Patent Application Publication No. 2014/0297058; U.S. Patent Application Publication No. 2014/0299665; U.S. Patent Application Publication No. 2014/0332590; U.S. Patent Application Publication No. 2014/0351317; U.S. Patent Application Publication No. 2014/0362184; U.S. Patent Application Publication No. 2014/0363015; U.S. Patent Application Publication No. 2014/0369511; U.S. Patent Application Publication No. 2014/0374483; U.S. Patent Application Publication No. 2014/0374485; U.S. Patent Application Publication No. 2015/0001301; U.S. Patent Application Publication No. 2015/0001304; U.S. Patent Application Publication No. 2015/0009338; U.S. Patent Application Publication No. 2015/0014416; U.S. Patent Application Publication No. 2015/0021397; U.S. Patent Application Publication No. 2015/0028104; U.S. Patent Application Publication No. 2015/0029002; U.S. Patent Application Publication No. 2015/0032709; U.S. Patent Application Publication No. 2015/0039309; U.S. Patent Application Publication No. 2015/0039878; U.S. Patent Application Publication No. 2015/0040378; U.S. Patent Application Publication No. 2015/0049347; U.S. Patent Application Publication No. 2015/0051992; U.S. Patent Application Publication No. 2015/0053769; U.S. Patent Application Publication No. 2015/0062366; U.S. Patent Application Publication No. 2015/0063215; U.S. Patent Application Publication No. 2015/0088522; U.S. Patent Application Publication No. 2015/0096872; U.S. Patent Application Publication No. 2015/0100196; U.S. Patent Application Publication No. 2015/0102109; U.S. Patent Application Publication No. 2015/0115035; U.S. Patent Application Publication No. 2015/0127791; U.S. Patent Application Publication No. 2015/0128116; U.S. Patent Application Publication No. 2015/0133047; U.S. Patent Application Publication No. 2015/0134470; U.S. Patent Application Publication No. 2015/0136851; U.S. Patent Application Publication No. 2015/0142492; U.S. Patent Application Publication No. 2015/0144692; U.S. Patent Application Publication No. 2015/0144698; U.S. Patent Application Publication No. 2015/0149946; U.S. Patent Application Publication No. 2015/0161429; U.S. Patent Application Publication No. 2015/0178523; U.S. Patent Application Publication No. 2015/0178537; U.S. Patent Application Publication No. 2015/0178685; U.S. Patent Application Publication No. 2015/0181109; U.S. Patent Application Publication No. 2015/0199957; U.S. Patent Application Publication No. 2015/0210199; U.S. Patent Application Publication No. 2015/0212565; U.S. Patent Application Publication No. 2015/0213647; U.S. Patent Application Publication No. 2015/0220753; U.S. Patent Application Publication No. 2015/0220901; U.S. Patent Application Publication No. 2015/0227189; U.S. Patent Application Publication No. 2015/0236984; U.S. Patent Application Publication No. 2015/0239348; U.S. Patent Application Publication No. 2015/0242658; U.S. Patent Application Publication No. 2015/0248572; U.S. Patent Application Publication No. 2015/0254485; U.S. Patent Application Publication No. 2015/0261643; U.S. Patent Application Publication No. 2015/0264624; U.S. Patent Application Publication No. 2015/0268971; U.S. Patent Application Publication No. 2015/0269402; U.S. Patent Application Publication No. 2015/0288689; U.S. Patent Application Publication No. 2015/0288896; U.S. Patent Application Publication No. 2015/0310243; U.S. Patent Application Publication No. 2015/0310244; U.S. Patent Application Publication No. 2015/0310389; U.S. Patent Application Publication No. 2015/0312780; U.S. Patent Application Publication No. 2015/0327012; U.S. Patent Application Publication No. 2016/0014251; U.S. Patent Application Publication No. 2016/0025697; U.S. Patent Application Publication No. 2016/0026838; U.S. Patent Application Publication No. 2016/0026839; U.S. Patent Application Publication No. 2016/0040982; U.S. Patent Application Publication No. 2016/0042241; U.S. Patent Application Publication No. 2016/0057230; U.S. Patent Application Publication No. 2016/0062473; U.S. Patent Application Publication No. 2016/0070944; U.S. Patent Application Publication No. 2016/0092805; U.S. Patent Application Publication No. 2016/0101936; U.S. Patent Application Publication No. 2016/0104019; U.S. Patent Application Publication No. 2016/0104274; U.S. Patent Application Publication No. 2016/0109219; U.S. Patent Application Publication No. 2016/0109220; U.S. Patent Application Publication No. 2016/0109224; U.S. Patent Application Publication No. 2016/0112631; U.S. Patent Application Publication No. 2016/0112643; U.S. Patent Application Publication No. 2016/0117627; U.S. Patent Application Publication No. 2016/0124516; U.S. Patent Application Publication No. 2016/0125217; U.S. Patent Application Publication No. 2016/0125342; U.S. Patent Application Publication No. 2016/0125873; U.S. Patent Application Publication No. 2016/0133253; U.S. Patent Application Publication No. 2016/0171597; U.S. Patent Application Publication No. 2016/0171666; U.S. Patent Application Publication No. 2016/0171720; U.S. Patent Application Publication No. 2016/0171775; U.S. Patent Application Publication No. 2016/0171777; U.S. Patent Application Publication No. 2016/0174674; U.S. Patent Application Publication No. 2016/0178479; U.S. Patent Application Publication No. 2016/0178685; U.S. Patent Application Publication No. 2016/0178707; U.S. Patent Application Publication No. 2016/0179132; U.S. Patent Application Publication No. 2016/0179143; U.S. Patent Application Publication No. 2016/0179368; U.S. Patent Application Publication No. 2016/0179378; U.S. Patent Application Publication No. 2016/0180130; U.S. Patent Application Publication No. 2016/0180133; U.S. Patent Application Publication No. 2016/0180136; U.S. Patent Application Publication No. 2016/0180594; U.S. Patent Application Publication No. 2016/0180663; U.S. Patent Application Publication No. 2016/0180678; U.S. Patent Application Publication No. 2016/0180713; U.S. Patent Application Publication No. 2016/0185136; U.S. Patent Application Publication No. 2016/0185291; U.S. Patent Application Publication No. 2016/0186926; U.S. Patent Application Publication No. 2016/0188861; U.S. Patent Application Publication No. 2016/0188939; U.S. Patent Application Publication No. 2016/0188940; U.S. Patent Application Publication No. 2016/0188941; U.S. Patent Application Publication No. 2016/0188942; U.S. Patent Application Publication No. 2016/0188943; U.S. Patent Application Publication No. 2016/0188944; U.S. Patent Application Publication No. 2016/0189076; U.S. Patent Application Publication No. 2016/0189087; U.S. Patent Application Publication No. 2016/0189088; U.S. Patent Application Publication No. 2016/0189092; U.S. Patent Application Publication No. 2016/0189284; U.S. Patent Application Publication No. 2016/0189288; U.S. Patent Application Publication No. 2016/0189366; U.S. Patent Application Publication No. 2016/0189443; U.S. Patent Application Publication No. 2016/0189447; U.S. Patent Application Publication No. 2016/0189489; U.S. Patent Application Publication No. 2016/0192051; U.S. Patent Application Publication No. 2016/0202951; U.S. Patent Application Publication No. 2016/0202958; U.S. Patent Application Publication No. 2016/0202959; U.S. Patent Application Publication No. 2016/0203021; U.S. Patent Application Publication No. 2016/0203429; U.S. Patent Application Publication No. 2016/0203797; U.S. Patent Application Publication No. 2016/0203820; U.S. Patent Application Publication No. 2016/0204623; U.S. Patent Application Publication No. 2016/0204636; U.S. Patent Application Publication No. 2016/0204638; U.S. Patent Application Publication No. 2016/0227912; U.S. Patent Application Publication No. 2016/0232891; U.S. Patent Application Publication No. 2016/0292477; U.S. Patent Application Publication No. 2016/0294779; U.S. Patent Application Publication No. 2016/0306769; U.S. Patent Application Publication No. 2016/0314276; U.S. Patent Application Publication No. 2016/0314294; U.S. Patent Application Publication No. 2016/0316190; U.S. Patent Application Publication No. 2016/0323310; U.S. Patent Application Publication No. 2016/0325677; U.S. Patent Application Publication No. 2016/0327614; U.S. Patent Application Publication No. 2016/0327930; U.S. Patent Application Publication No. 2016/0328762; U.S. Patent Application Publication No. 2016/0330218; U.S. Patent Application Publication No. 2016/0343163; U.S. Patent Application Publication No. 2016/0343176; U.S. Patent Application Publication No. 2016/0364914; U.S. Patent Application Publication No. 2016/0370220; U.S. Patent Application Publication No. 2016/0372282; U.S. Patent Application Publication No. 2016/0373847; U.S. Patent Application Publication No. 2016/0377414; U.S. Patent Application Publication No. 2016/0377417; U.S. Patent Application Publication No. 2017/0010141; U.S. Patent Application Publication No. 2017/0010328; U.S. Patent Application Publication No. 2017/0010780; U.S. Patent Application Publication No. 2017/0016714; U.S. Patent Application Publication No. 2017/0018094; U.S. Patent Application Publication No. 2017/0046603; U.S. Patent Application Publication No. 2017/0047864; U.S. Patent Application Publication No. 2017/0053146; U.S. Patent Application Publication No. 2017/0053147; U.S. Patent Application Publication No. 2017/0053647; U.S. Patent Application Publication No. 2017/0055606; U.S. Patent Application Publication No. 2017/0060316; U.S. Patent Application Publication No. 2017/0061961; U.S. Patent Application Publication No. 2017/0064634; U.S. Patent Application Publication No. 2017/0083730; U.S. Patent Application Publication No. 2017/0091502; U.S. Patent Application Publication No. 2017/0091706; U.S. Patent Application Publication No. 2017/0091741; U.S. Patent Application Publication No. 2017/0091904; U.S. Patent Application Publication No. 2017/0092908; U.S. Patent Application Publication No. 2017/0094238; U.S. Patent Application Publication No. 2017/0098947; U.S. Patent Application Publication No. 2017/0100949; U.S. Patent Application Publication No. 2017/0108838; U.S. Patent Application Publication No. 2017/0108895; U.S. Patent Application Publication No. 2017/0118355; U.S. Patent Application Publication No. 2017/0123598; U.S. Patent Application Publication No. 2017/0124369; U.S. Patent Application Publication No. 2017/0124396; U.S. Patent Application Publication No. 2017/0124687; U.S. Patent Application Publication No. 2017/0126873; U.S. Patent Application Publication No. 2017/0126904; U.S. Patent Application Publication No. 2017/0139012; U.S. Patent Application Publication No. 2017/0140329; U.S. Patent Application Publication No. 2017/0140731; U.S. Patent Application Publication No. 2017/0147847; U.S. Patent Application Publication No. 2017/0150124; U.S. Patent Application Publication No. 2017/0169198; U.S. Patent Application Publication No. 2017/0171035; U.S. Patent Application Publication No. 2017/0171703; U.S. Patent Application Publication No. 2017/0171803; U.S. Patent Application Publication No. 2017/0180359; U.S. Patent Application Publication No. 2017/0180577; U.S. Patent Application Publication No. 2017/0181299; U.S. Patent Application Publication No. 2017/0190192; U.S. Patent Application Publication No. 2017/0193432; U.S. Patent Application Publication No. 2017/0193461; U.S. Patent Application Publication No. 2017/0193727; U.S. Patent Application Publication No. 2017/0199266; U.S. Patent Application Publication No. 2017/0200108; and U.S. Patent Application Publication No. 2017/0200275.


In the specification and/or figures, typical embodiments of the invention have been disclosed. The present invention is not limited to such exemplary embodiments. The use of the term “and/or” includes any and all combinations of one or more of the associated listed items. The figures are schematic representations and so are not necessarily drawn to scale. Unless otherwise noted, specific terms have been used in a generic and descriptive sense and not for purposes of limitation.

Claims
  • 1. A method for determining whether a system clock has been altered, the method comprising the steps of: capturing, with a computer comprising a system clock, an initial system time and an initial counter value when a device is connected to the computer, wherein the initial system time and the initial counter value are based on the system clock;receiving, with the computer, information obtained by the device;capturing, with the computer, a current system time and a current counter value when the information is obtained, wherein the current system time and the current counter value are based on the system clock;determining, with the computer, a first time-calculation representing a difference in time between the initial system time and the current system time;determining, with the computer, a second time-calculation representing a difference between the initial counter value and the current counter value;comparing, with the computer, the first time-calculation and the second time-calculation to determine that a mismatch exists; anddetermining that the system clock has been altered based on the comparison.
  • 2. The method of claim 1, further comprising the step of communicating a data entry from the device to the computer, wherein the computer is configured to log the data entry with an electronic timestamp.
  • 3. The method of claim 2, wherein the device is a certified dimensioning device or multi-dimensional measuring device (MDMD).
  • 4. The method of claim 2, wherein, in response to determining that the system clock has been altered, the method further comprises the step of communicating time alteration information from the computer to the device.
  • 5. The method of claim 4, wherein, in response to determining that the system clock has been altered, the method further comprises the step of preventing the device from obtaining additional data.
  • 6. The method of claim 1, wherein, when the mismatch exists, the method further comprises the step of recording information regarding the mismatch in a time integrity log.
  • 7. The method of claim 1, wherein the mismatch is detected when the difference between the first time-calculation and the second time-calculation exceeds a predetermined threshold.
  • 8. The method of claim 1, further comprising the steps of: starting a loop having a predetermined time period;capturing an initial system time at the start of the loop;detecting an ending system time at the end of the loop;calculating a difference in time between the initial system time and the ending system time;determining whether the calculated difference is the same as other calculated differences for other loops having the predetermined time period; anddetecting that the system clock has been altered when the calculated difference is not the same as the other calculated differences.
  • 9. The method of claim 1, further comprising the steps of: comparing a timestamp related to a particular event with a timestamp related to another event immediately preceding the particular event; anddetermining an alteration incident when the timestamp related to the particular event includes an earlier time than the time of the timestamp related to the other event.
  • 10. A non-transitory computer readable medium for storing a timestamp verifying program that determines whether a system clock of a computer has been altered, the non-transitory computer readable medium configured to allow the computer to: start a loop having a predetermined time period;capture an initial system time at the start of the loop;capture an ending system time at the end of the loop;calculate a difference in time between the initial system time and the ending system time;determine whether the calculated difference is the same as other calculated differences for other loops having the predetermined time period; anddetermine that the system clock has been altered when the calculated difference is not the same as the other calculated differences.
  • 11. The non-transitory computer readable medium of claim 10, further configured to allow the computer to receive a data entry from a metrology device and log the data entry with an electronic timestamp.
  • 12. The non-transitory computer readable medium of claim 10, further configured to allow the computer to: capture an initial system time and an initial counter value;log an event;capture a current system time when the event is logged;sample a current counter value when the event is logged;determine a first time-calculation representing a difference in time between the initial system time and the current system time;determine a second time-calculation representing a difference between the initial counter value and the current counter value; andcompare the first time-calculation and the second time-calculation to determine if a mismatch exists.
  • 13. The non-transitory computer readable medium of claim 10, further configured to allow the computer to: compare a timestamp related to a particular event with a timestamp related to another event immediately preceding the particular event; anddetermine an alteration incident when the timestamp related to the particular event includes an earlier time than the time of the timestamp related to the other event.
  • 14. A system comprising: a device configured to obtain information related to an event; anda computer connected to the device, wherein the computer comprises a system clock for providing a system time, and wherein the computer is configured to: capture an initial system time and an initial counter value when a device is connected to the computer, wherein the initial system time and the initial counter value are based on the system clock;receive information obtained by the device;capture a current system time and a current counter value when the information is obtained, wherein the current system time and the current counter value are based on the system clock;determine a first time-calculation representing a difference in time between the initial system time and the current system time;determine a second time-calculation representing a difference between the initial counter value and the current counter value;compare the first time-calculation and the second time-calculation to determine that a mismatch exists; anddetermine that the system clock has been altered based on the comparison.
  • 15. The system of claim 14, wherein the device is a certified metrology device for determining dimensions of an object and wherein the information related to the event includes at least measurements of the dimensions of the object.
  • 16. The system of claim 14, wherein the computer further comprises a time integrity log, wherein, when the computer determines that the system clock has been altered, the computer is configured to record information regarding a concurrent event in the time integrity log.
  • 17. The system of claim 14, wherein the computer comprises a data log configured to store the information related to the event.
  • 18. The non-transitory computer readable medium of claim 10, wherein the mismatch is detected when the difference between the first time-calculation and the second time-calculation exceeds a predetermined threshold.
  • 19. The system of claim 14, wherein the mismatch is detected when the difference between the first time-calculation and the second time-calculation exceeds a predetermined threshold.
  • 20. The system of claim 14, wherein the computer is further configured to: start a loop having a predetermined time period;capture an initial system time at the start of the loop;detect an ending system time at the end of the loop;calculate a difference in time between the initial system time and the ending system time;determine whether the calculated difference is the same as other calculated differences for other loops having the predetermined time period; anddetect that the system clock has been altered when the calculated difference is not the same as the other calculated differences.
US Referenced Citations (655)
Number Name Date Kind
5040158 Lee Aug 1991 A
6832725 Gardiner et al. Dec 2004 B2
7128266 Zhu et al. Oct 2006 B2
7159783 Walczyk et al. Jan 2007 B2
7413127 Ehrhart et al. Aug 2008 B2
7726575 Wang et al. Jun 2010 B2
8294969 Plesko Oct 2012 B2
8317105 Kotlarsky et al. Nov 2012 B2
8322622 Liu Dec 2012 B2
8366005 Kotlarsky et al. Feb 2013 B2
8371507 Haggerty et al. Feb 2013 B2
8376233 Van Horn et al. Feb 2013 B2
8381979 Franz Feb 2013 B2
8390909 Plesko Mar 2013 B2
8408464 Zhu et al. Apr 2013 B2
8408468 Horn et al. Apr 2013 B2
8408469 Good Apr 2013 B2
8424768 Rueblinger et al. Apr 2013 B2
8448863 Xian et al. May 2013 B2
8457013 Essinger et al. Jun 2013 B2
8459557 Havens et al. Jun 2013 B2
8469272 Kearney Jun 2013 B2
8474712 Kearney et al. Jul 2013 B2
8479992 Kotlarsky et al. Jul 2013 B2
8490877 Kearney Jul 2013 B2
8517271 Kotlarsky et al. Aug 2013 B2
8523076 Good Sep 2013 B2
8528818 Ehrhart et al. Sep 2013 B2
8544737 Gomez et al. Oct 2013 B2
8548420 Grunow et al. Oct 2013 B2
8550335 Samek et al. Oct 2013 B2
8550354 Gannon et al. Oct 2013 B2
8550357 Kearney Oct 2013 B2
8556174 Kosecki et al. Oct 2013 B2
8556176 Van Horn et al. Oct 2013 B2
8556177 Hussey et al. Oct 2013 B2
8559767 Barber et al. Oct 2013 B2
8561895 Gomez et al. Oct 2013 B2
8561903 Sauerwein Oct 2013 B2
8561905 Edmonds et al. Oct 2013 B2
8565107 Pease et al. Oct 2013 B2
8571307 Li et al. Oct 2013 B2
8579200 Samek et al. Nov 2013 B2
8583924 Caballero et al. Nov 2013 B2
8584945 Wang et al. Nov 2013 B2
8587595 Wang Nov 2013 B2
8587697 Hussey et al. Nov 2013 B2
8588869 Sauerwein et al. Nov 2013 B2
8590789 Nahill et al. Nov 2013 B2
8596539 Havens et al. Dec 2013 B2
8596542 Havens et al. Dec 2013 B2
8596543 Havens et al. Dec 2013 B2
8599271 Havens et al. Dec 2013 B2
8599957 Peake et al. Dec 2013 B2
8600158 Li et al. Dec 2013 B2
8600167 Showering Dec 2013 B2
8602309 Longacre et al. Dec 2013 B2
8608053 Meier et al. Dec 2013 B2
8608071 Liu et al. Dec 2013 B2
8611309 Wang et al. Dec 2013 B2
8615487 Gomez et al. Dec 2013 B2
8621123 Caballero Dec 2013 B2
8622303 Meier et al. Jan 2014 B2
8628013 Ding Jan 2014 B2
8628015 Wang et al. Jan 2014 B2
8628016 Winegar Jan 2014 B2
8629926 Wang Jan 2014 B2
8630491 Longacre et al. Jan 2014 B2
8635309 Berthiaume et al. Jan 2014 B2
8636200 Kearney Jan 2014 B2
8636212 Nahill et al. Jan 2014 B2
8636215 Ding et al. Jan 2014 B2
8636224 Wang Jan 2014 B2
8638806 Wang et al. Jan 2014 B2
8640958 Lu et al. Feb 2014 B2
8640960 Wang et al. Feb 2014 B2
8643717 Li et al. Feb 2014 B2
8646692 Meier et al. Feb 2014 B2
8646694 Wang et al. Feb 2014 B2
8657200 Ren et al. Feb 2014 B2
8659397 Vargo et al. Feb 2014 B2
8668149 Good Mar 2014 B2
8678285 Kearney Mar 2014 B2
8678286 Smith et al. Mar 2014 B2
8682077 Longacre Mar 2014 B1
D702237 Oberpriller et al. Apr 2014 S
8687282 Feng et al. Apr 2014 B2
8692927 Pease et al. Apr 2014 B2
8695880 Bremer et al. Apr 2014 B2
8698949 Grunow et al. Apr 2014 B2
8702000 Barber et al. Apr 2014 B2
8717494 Gannon May 2014 B2
8720783 Biss et al. May 2014 B2
8723804 Fletcher et al. May 2014 B2
8723904 Marty et al. May 2014 B2
8727223 Wang May 2014 B2
8740082 Wilz Jun 2014 B2
8740085 Furlong et al. Jun 2014 B2
8746563 Hennick et al. Jun 2014 B2
8750445 Peake et al. Jun 2014 B2
8752766 Xian et al. Jun 2014 B2
8756059 Braho et al. Jun 2014 B2
8757495 Qu et al. Jun 2014 B2
8760563 Koziol et al. Jun 2014 B2
8763909 Reed Jul 2014 B2
8777108 Coyle Jul 2014 B2
8777109 Oberpriller et al. Jul 2014 B2
8779898 Havens et al. Jul 2014 B2
8781520 Payne et al. Jul 2014 B2
8783573 Havens et al. Jul 2014 B2
8789757 Barten Jul 2014 B2
8789758 Hawley et al. Jul 2014 B2
8789759 Xian et al. Jul 2014 B2
8794520 Wang et al. Aug 2014 B2
8794522 Ehrhart Aug 2014 B2
8794525 Amundsen et al. Aug 2014 B2
8794526 Wang et al. Aug 2014 B2
8798367 Ellis Aug 2014 B2
8807431 Wang et al. Aug 2014 B2
8807432 Van Horn et al. Aug 2014 B2
8820630 Qu et al. Sep 2014 B2
8822848 Meagher Sep 2014 B2
8824692 Sheerin et al. Sep 2014 B2
8824696 Braho Sep 2014 B2
8842849 Wahl et al. Sep 2014 B2
8844822 Kotlarsky et al. Sep 2014 B2
8844823 Fritz et al. Sep 2014 B2
8849019 Li et al. Sep 2014 B2
D716285 Chaney et al. Oct 2014 S
8851383 Yeakley et al. Oct 2014 B2
8854633 Laffargue Oct 2014 B2
8866963 Grunow et al. Oct 2014 B2
8868421 Braho et al. Oct 2014 B2
8868519 Maloy et al. Oct 2014 B2
8868802 Barten Oct 2014 B2
8868803 Caballero Oct 2014 B2
8869288 Conley et al. Oct 2014 B2
8870074 Gannon Oct 2014 B1
8879639 Sauerwein Nov 2014 B2
8880426 Smith Nov 2014 B2
8881983 Havens et al. Nov 2014 B2
8881987 Wang Nov 2014 B2
8903172 Smith Dec 2014 B2
8908995 Benos et al. Dec 2014 B2
8910870 Li et al. Dec 2014 B2
8910875 Ren et al. Dec 2014 B2
8914290 Hendrickson et al. Dec 2014 B2
8914788 Pettinelli et al. Dec 2014 B2
8915439 Feng et al. Dec 2014 B2
8915444 Havens et al. Dec 2014 B2
8916789 Woodburn Dec 2014 B2
8918250 Hollifield Dec 2014 B2
8918564 Caballero Dec 2014 B2
8925818 Kosecki et al. Jan 2015 B2
8939374 Jovanovski et al. Jan 2015 B2
8942480 Ellis Jan 2015 B2
8944313 Williams et al. Feb 2015 B2
8944327 Meier et al. Feb 2015 B2
8944332 Harding et al. Feb 2015 B2
8950678 Germaine et al. Feb 2015 B2
D723560 Zhou et al. Mar 2015 S
8967468 Gomez et al. Mar 2015 B2
8971346 Sevier Mar 2015 B2
8976030 Cunningham et al. Mar 2015 B2
8976368 Akel et al. Mar 2015 B2
8978981 Guan Mar 2015 B2
8978983 Bremer et al. Mar 2015 B2
8978984 Hennick et al. Mar 2015 B2
8985456 Zhu et al. Mar 2015 B2
8985457 Soule et al. Mar 2015 B2
8985459 Kearney et al. Mar 2015 B2
8985461 Gelay et al. Mar 2015 B2
8988578 Showering Mar 2015 B2
8988590 Gillet et al. Mar 2015 B2
8991704 Hopper et al. Mar 2015 B2
8996194 Davis et al. Mar 2015 B2
8996384 Funyak et al. Mar 2015 B2
8998091 Edmonds et al. Apr 2015 B2
9002641 Showering Apr 2015 B2
9007368 Laffargue et al. Apr 2015 B2
9010641 Qu et al. Apr 2015 B2
9015513 Murawski et al. Apr 2015 B2
9016576 Brady et al. Apr 2015 B2
D730357 Fitch et al. May 2015 S
9022288 Nahill et al. May 2015 B2
9030964 Essinger et al. May 2015 B2
9033240 Smith et al. May 2015 B2
9033242 Gillet et al. May 2015 B2
9036054 Koziol et al. May 2015 B2
9037344 Chamberlin May 2015 B2
9038911 Xian et al. May 2015 B2
9038915 Smith May 2015 B2
D730901 Oberpriller et al. Jun 2015 S
D730902 Fitch et al. Jun 2015 S
9047098 Barten Jun 2015 B2
9047359 Caballero et al. Jun 2015 B2
9047420 Caballero Jun 2015 B2
9047525 Barber Jun 2015 B2
9047531 Showering et al. Jun 2015 B2
9049640 Wang et al. Jun 2015 B2
9053055 Caballero Jun 2015 B2
9053378 Hou et al. Jun 2015 B1
9053380 Xian et al. Jun 2015 B2
9057641 Amundsen et al. Jun 2015 B2
9058526 Powilleit Jun 2015 B2
9061527 Tobin et al. Jun 2015 B2
9064165 Havens et al. Jun 2015 B2
9064167 Xian et al. Jun 2015 B2
9064168 Todeschini et al. Jun 2015 B2
9064254 Todeschini et al. Jun 2015 B2
9066032 Wang Jun 2015 B2
9070032 Corcoran Jun 2015 B2
D734339 Zhou et al. Jul 2015 S
D734751 Oberpriller et al. Jul 2015 S
9076459 Braho et al. Jul 2015 B2
9079423 Bouverie et al. Jul 2015 B2
9080856 Laffargue Jul 2015 B2
9082023 Feng et al. Jul 2015 B2
9084032 Rautiola et al. Jul 2015 B2
9087250 Coyle Jul 2015 B2
9092681 Havens et al. Jul 2015 B2
9092682 Wilz et al. Jul 2015 B2
9092683 Koziol et al. Jul 2015 B2
9093141 Liu Jul 2015 B2
D737321 Lee Aug 2015 S
9098763 Lu et al. Aug 2015 B2
9104929 Todeschini Aug 2015 B2
9104934 Li et al. Aug 2015 B2
9107484 Chaney Aug 2015 B2
9111159 Liu et al. Aug 2015 B2
9111166 Cunningham Aug 2015 B2
9135483 Liu et al. Sep 2015 B2
9137009 Gardiner Sep 2015 B1
9141839 Xian et al. Sep 2015 B2
9147096 Wang Sep 2015 B2
9148474 Skvoretz Sep 2015 B2
9158000 Sauerwein Oct 2015 B2
9158340 Reed et al. Oct 2015 B2
9158953 Gillet et al. Oct 2015 B2
9159059 Daddabbo et al. Oct 2015 B2
9165174 Huck Oct 2015 B2
9171543 Emerick et al. Oct 2015 B2
9183425 Wang Nov 2015 B2
9189669 Zhu et al. Nov 2015 B2
9195844 Todeschini et al. Nov 2015 B2
9202458 Braho et al. Dec 2015 B2
9208366 Liu Dec 2015 B2
9208367 Wang Dec 2015 B2
9219836 Bouverie et al. Dec 2015 B2
9224022 Ackley et al. Dec 2015 B2
9224024 Bremer et al. Dec 2015 B2
9224027 Van Horn et al. Dec 2015 B2
D747321 London et al. Jan 2016 S
9230140 Ackley Jan 2016 B1
9235553 Fitch et al. Jan 2016 B2
9239950 Fletcher Jan 2016 B2
9245492 Ackley et al. Jan 2016 B2
9443123 Hejl Jan 2016 B2
9248640 Heng Feb 2016 B2
9250652 London et al. Feb 2016 B2
9250712 Todeschini Feb 2016 B1
9251411 Todeschini Feb 2016 B2
9258033 Showering Feb 2016 B2
9262633 Todeschini et al. Feb 2016 B1
9262660 Lu et al. Feb 2016 B2
9262662 Chen et al. Feb 2016 B2
9269036 Bremer Feb 2016 B2
9270782 Hala et al. Feb 2016 B2
9274812 Doren et al. Mar 2016 B2
9275388 Havens et al. Mar 2016 B2
9277668 Feng et al. Mar 2016 B2
9280693 Feng et al. Mar 2016 B2
9286496 Smith Mar 2016 B2
9297900 Jiang Mar 2016 B2
9298964 Li et al. Mar 2016 B2
9301427 Feng et al. Mar 2016 B2
D754205 Nguyen et al. Apr 2016 S
D754206 Nguyen et al. Apr 2016 S
9304376 Anderson Apr 2016 B2
9310609 Rueblinger et al. Apr 2016 B2
9313377 Todeschini et al. Apr 2016 B2
9317037 Byford et al. Apr 2016 B2
9319548 Showering et al. Apr 2016 B2
D757009 Oberpriller et al. May 2016 S
9342723 Liu et al. May 2016 B2
9342724 McCloskey May 2016 B2
9361882 Ressler et al. Jun 2016 B2
9365381 Colonel et al. Jun 2016 B2
9373018 Colavito et al. Jun 2016 B2
9375945 Bowles Jun 2016 B1
9378403 Wang et al. Jun 2016 B2
D760719 Zhou et al. Jul 2016 S
9360304 Chang et al. Jul 2016 B2
9383848 Daghigh Jul 2016 B2
9384374 Bianconi Jul 2016 B2
9390304 Chang et al. Jul 2016 B2
9390596 Todeschini Jul 2016 B1
D762604 Fitch et al. Aug 2016 S
9411386 Sauerwein Aug 2016 B2
9412242 Van Horn et al. Aug 2016 B2
9418269 Havens et al. Aug 2016 B2
9418270 Van Volkinburg et al. Aug 2016 B2
9423318 Lui et al. Aug 2016 B2
D766244 Zhou et al. Sep 2016 S
9443222 Singel et al. Sep 2016 B2
9454689 McCloskey et al. Sep 2016 B2
9464885 Lloyd et al. Oct 2016 B2
9465967 Xian et al. Oct 2016 B2
9478113 Xie et al. Oct 2016 B2
9478983 Kather et al. Oct 2016 B2
D771631 Fitch et al. Nov 2016 S
9481186 Bouverie et al. Nov 2016 B2
9487113 Schukalski Nov 2016 B2
9488986 Solanki Nov 2016 B1
9489782 Payne et al. Nov 2016 B2
9490540 Davies et al. Nov 2016 B1
9491729 Rautiola et al. Nov 2016 B2
9497092 Gomez et al. Nov 2016 B2
9507974 Todeschini Nov 2016 B1
9519814 Cudzilo Dec 2016 B2
9521331 Bessettes et al. Dec 2016 B2
9530038 Xian et al. Dec 2016 B2
D777166 Bidwell et al. Jan 2017 S
9558386 Yeakley Jan 2017 B2
9572901 Todeschini Feb 2017 B2
9606581 Howe et al. Mar 2017 B1
D783601 Schulte et al. Apr 2017 S
D785617 Bidwell et al. May 2017 S
D785636 Oberpriller et al. May 2017 S
9646189 Lu et al. May 2017 B2
9646191 Unemyr et al. May 2017 B2
9652648 Ackley et al. May 2017 B2
9652653 Todeschini et al. May 2017 B2
9656487 Ho et al. May 2017 B2
9659198 Giordano et al. May 2017 B2
D790505 Vargo et al. Jun 2017 S
D790546 Zhou et al. Jun 2017 S
9680282 Hanenburg Jun 2017 B2
9697401 Feng et al. Jul 2017 B2
9701140 Alaganchetty et al. Jul 2017 B1
20020169974 McKune Nov 2002 A1
20070063048 Havens et al. Mar 2007 A1
20070168687 Brokish Jul 2007 A1
20090134221 Zhu et al. May 2009 A1
20090287942 Betouin et al. Nov 2009 A1
20100177076 Essinger et al. Jul 2010 A1
20100177080 Essinger et al. Jul 2010 A1
20100177707 Essinger et al. Jul 2010 A1
20100177749 Essinger et al. Jul 2010 A1
20110016346 Lee Jan 2011 A1
20110169999 Grunow et al. Jul 2011 A1
20110202554 Powilleit et al. Aug 2011 A1
20120111946 Golant May 2012 A1
20120168512 Kotlarsky et al. Jul 2012 A1
20120193423 Samek Aug 2012 A1
20120194692 Mers et al. Aug 2012 A1
20120203647 Smith Aug 2012 A1
20120223141 Good et al. Sep 2012 A1
20130004142 Grab Jan 2013 A1
20130043312 Van Horn Feb 2013 A1
20130075168 Amundsen et al. Mar 2013 A1
20130175341 Kearney et al. Jul 2013 A1
20130175343 Good Jul 2013 A1
20130257744 Daghigh et al. Oct 2013 A1
20130257759 Daghigh Oct 2013 A1
20130270346 Xian et al. Oct 2013 A1
20130292475 Kotlarsky et al. Nov 2013 A1
20130292477 Hennick et al. Nov 2013 A1
20130293539 Hunt et al. Nov 2013 A1
20130293540 Laffargue et al. Nov 2013 A1
20130306728 Thuries et al. Nov 2013 A1
20130306731 Pedraro Nov 2013 A1
20130307964 Bremer et al. Nov 2013 A1
20130308625 Park et al. Nov 2013 A1
20130313324 Koziol et al. Nov 2013 A1
20130332524 Fiala et al. Dec 2013 A1
20130332996 Fiala et al. Dec 2013 A1
20140001267 Giordano et al. Jan 2014 A1
20140002828 Laffargue et al. Jan 2014 A1
20140025584 Liu et al. Jan 2014 A1
20140100813 Showering Jan 2014 A1
20140034734 Sauerwein Feb 2014 A1
20140036848 Pease et al. Feb 2014 A1
20140039693 Havens et al. Feb 2014 A1
20140049120 Kohtz et al. Feb 2014 A1
20140049635 Laffargue et al. Feb 2014 A1
20140061306 Wu et al. Mar 2014 A1
20140063289 Hussey et al. Mar 2014 A1
20140066136 Sauerwein et al. Mar 2014 A1
20140067692 Ye et al. Mar 2014 A1
20140070005 Nahill et al. Mar 2014 A1
20140071840 Venancio Mar 2014 A1
20140074746 Wang Mar 2014 A1
20140076974 Havens et al. Mar 2014 A1
20140078342 Li et al. Mar 2014 A1
20140098792 Wang et al. Apr 2014 A1
20140100774 Showering Apr 2014 A1
20140103115 Meier et al. Apr 2014 A1
20140104413 McCloskey et al. Apr 2014 A1
20140104414 McCloskey et al. Apr 2014 A1
20140104416 Giordano et al. Apr 2014 A1
20140106725 Sauerwein Apr 2014 A1
20140108010 Maltseff et al. Apr 2014 A1
20140108402 Gomez et al. Apr 2014 A1
20140108682 Caballero Apr 2014 A1
20140110485 Toa et al. Apr 2014 A1
20140114530 Fitch et al. Apr 2014 A1
20140125853 Wang May 2014 A1
20140125999 Longacre et al. May 2014 A1
20140129378 Richardson May 2014 A1
20140131443 Smith May 2014 A1
20140131444 Wang May 2014 A1
20140133379 Wang et al. May 2014 A1
20140136208 Maltseff et al. May 2014 A1
20140140585 Wang May 2014 A1
20140152882 Samek et al. Jun 2014 A1
20140158770 Sevier et al. Jun 2014 A1
20140159869 Zumsteg et al. Jun 2014 A1
20140166755 Liu et al. Jun 2014 A1
20140166757 Smith Jun 2014 A1
20140166759 Liu et al. Jun 2014 A1
20140168787 Wang et al. Jun 2014 A1
20140175165 Havens et al. Jun 2014 A1
20140191684 Valois Jul 2014 A1
20140191913 Ge et al. Jul 2014 A1
20140197239 Havens et al. Jul 2014 A1
20140197304 Feng et al. Jul 2014 A1
20140204268 Grunow et al. Jul 2014 A1
20140214631 Hansen Jul 2014 A1
20140217166 Berthiaume et al. Aug 2014 A1
20140217180 Liu Aug 2014 A1
20140231500 Ehrhart et al. Aug 2014 A1
20140247315 Marty et al. Sep 2014 A1
20140263493 Amurgis et al. Sep 2014 A1
20140263645 Smith et al. Sep 2014 A1
20140270196 Braho et al. Sep 2014 A1
20140270229 Braho Sep 2014 A1
20140278387 DiGregorio Sep 2014 A1
20140282210 Bianconi Sep 2014 A1
20140288933 Braho et al. Sep 2014 A1
20140297058 Barker et al. Oct 2014 A1
20140299665 Barber et al. Oct 2014 A1
20140332590 Wang et al. Nov 2014 A1
20140351317 Smith et al. Nov 2014 A1
20140362184 Jovanovski et al. Dec 2014 A1
20140363015 Braho Dec 2014 A1
20140369511 Sheerin et al. Dec 2014 A1
20140374483 Lu Dec 2014 A1
20140374485 Xian et al. Dec 2014 A1
20150001301 Ouyang Jan 2015 A1
20150009338 Laffargue et al. Jan 2015 A1
20150014416 Kotlarsky et al. Jan 2015 A1
20150021397 Rueblinger et al. Jan 2015 A1
20150028104 Ma et al. Jan 2015 A1
20150029002 Yeakley et al. Jan 2015 A1
20150032709 Maloy et al. Jan 2015 A1
20150039309 Braho et al. Feb 2015 A1
20150040378 Saber et al. Feb 2015 A1
20150049347 Laffargue et al. Feb 2015 A1
20150051992 Smith Feb 2015 A1
20150053769 Thuries et al. Feb 2015 A1
20150062366 Liu et al. Mar 2015 A1
20150063215 Wang Mar 2015 A1
20150088522 Hendrickson et al. Mar 2015 A1
20150096872 Woodburn Apr 2015 A1
20150100196 Hollifield Apr 2015 A1
20150115035 Meier et al. Apr 2015 A1
20150127791 Kosecki et al. May 2015 A1
20150128116 Chen et al. May 2015 A1
20150133047 Smith et al. May 2015 A1
20150134470 Hejl et al. May 2015 A1
20150136851 Harding et al. May 2015 A1
20150142492 Kumar May 2015 A1
20150144692 Hejl May 2015 A1
20150144698 Teng et al. May 2015 A1
20150149946 Benos et al. May 2015 A1
20150161429 Xian Jun 2015 A1
20150178523 Gelay et al. Jun 2015 A1
20150178537 El et al. Jun 2015 A1
20150178685 Krumel et al. Jun 2015 A1
20150181109 Gillet et al. Jun 2015 A1
20150186703 Chen et al. Jul 2015 A1
20150199957 Funyak et al. Jul 2015 A1
20150210199 Payne Jul 2015 A1
20150212565 Murawski et al. Jul 2015 A1
20150213647 Laffargue et al. Jul 2015 A1
20150220753 Zhu et al. Aug 2015 A1
20150220901 Gomez et al. Aug 2015 A1
20150227189 Davis et al. Aug 2015 A1
20150236984 Sevier Aug 2015 A1
20150239348 Chamberlin Aug 2015 A1
20150242658 Nahill et al. Aug 2015 A1
20150248572 Soule et al. Sep 2015 A1
20150254485 Feng et al. Sep 2015 A1
20150261643 Caballero et al. Sep 2015 A1
20150264624 Wang et al. Sep 2015 A1
20150268971 Barten Sep 2015 A1
20150269402 Barber et al. Sep 2015 A1
20150288689 Todeschini et al. Oct 2015 A1
20150288896 Wang Oct 2015 A1
20150310243 Ackley Oct 2015 A1
20150310244 Xian et al. Oct 2015 A1
20150310389 Crimm et al. Oct 2015 A1
20150312780 Wang et al. Oct 2015 A1
20150327012 Bian et al. Nov 2015 A1
20160014251 Hejl Jan 2016 A1
20160025697 Alt et al. Jan 2016 A1
20160026838 Gillet et al. Jan 2016 A1
20160026839 Qu et al. Jan 2016 A1
20160040982 Li et al. Feb 2016 A1
20160042241 Todeschini Feb 2016 A1
20160057230 Todeschini et al. Feb 2016 A1
20160062473 Bouchat et al. Mar 2016 A1
20160092805 Geisler et al. Mar 2016 A1
20160101936 Chamberlin Apr 2016 A1
20160102975 McCloskey et al. Apr 2016 A1
20160104019 Todeschini et al. Apr 2016 A1
20160104274 Jovanovski et al. Apr 2016 A1
20160109219 Ackley et al. Apr 2016 A1
20160109220 Laffargue Apr 2016 A1
20160109224 Thuries et al. Apr 2016 A1
20160112631 Ackley et al. Apr 2016 A1
20160112643 Laffargue et al. Apr 2016 A1
20160117627 Raj et al. Apr 2016 A1
20160124516 Schoon et al. May 2016 A1
20160125217 Todeschini May 2016 A1
20160125342 Miller et al. May 2016 A1
20160133253 Braho et al. May 2016 A1
20160171597 Todeschini Jun 2016 A1
20160171666 McCloskey Jun 2016 A1
20160171720 Todeschini Jun 2016 A1
20160171775 Todeschini et al. Jun 2016 A1
20160171777 Todeschini et al. Jun 2016 A1
20160174674 Oberpriller et al. Jun 2016 A1
20160178479 Goldsmith Jun 2016 A1
20160178685 Young et al. Jun 2016 A1
20160178707 Young et al. Jun 2016 A1
20160179132 Harr et al. Jun 2016 A1
20160179143 Bidwell et al. Jun 2016 A1
20160179368 Roeder Jun 2016 A1
20160179378 Kent et al. Jun 2016 A1
20160180130 Bremer Jun 2016 A1
20160180133 Oberpriller et al. Jun 2016 A1
20160180136 Meier et al. Jun 2016 A1
20160180594 Todeschini Jun 2016 A1
20160180663 McMahan et al. Jun 2016 A1
20160180678 Ackley et al. Jun 2016 A1
20160180713 Bernhardt et al. Jun 2016 A1
20160185136 Ng et al. Jun 2016 A1
20160185291 Chamberlin Jun 2016 A1
20160186926 Oberpriller et al. Jun 2016 A1
20160188861 Todeschini Jun 2016 A1
20160188939 Sailors et al. Jun 2016 A1
20160188940 Lu et al. Jun 2016 A1
20160188941 Todeschini et al. Jun 2016 A1
20160188942 Good et al. Jun 2016 A1
20160188943 Linwood Jun 2016 A1
20160188944 Wilz et al. Jun 2016 A1
20160189076 Mellott et al. Jun 2016 A1
20160189087 Morton et al. Jun 2016 A1
20160189088 Percorari et al. Jun 2016 A1
20160189092 George et al. Jun 2016 A1
20160189284 Mellott et al. Jun 2016 A1
20160189288 Todeschini Jun 2016 A1
20160189366 Chamberlin et al. Jun 2016 A1
20160189443 Smith Jun 2016 A1
20160189447 Valenzuela Jun 2016 A1
20160189489 Au et al. Jun 2016 A1
20160191684 DiPiazza et al. Jun 2016 A1
20160192051 DiPiazza et al. Jun 2016 A1
20160125873 Braho et al. Jul 2016 A1
20160202951 Pike et al. Jul 2016 A1
20160202958 Zabel et al. Jul 2016 A1
20160202959 Doubleday et al. Jul 2016 A1
20160203021 Pike et al. Jul 2016 A1
20160203429 Mellott et al. Jul 2016 A1
20160203797 Pike et al. Jul 2016 A1
20160203820 Zabel et al. Jul 2016 A1
20160204623 Haggert et al. Jul 2016 A1
20160204636 Allen et al. Jul 2016 A1
20160204638 Miraglia et al. Jul 2016 A1
20160316190 McCloskey et al. Jul 2016 A1
20160227912 Oberpriller et al. Aug 2016 A1
20160232891 Pecorari Aug 2016 A1
20160292477 Bidwell Oct 2016 A1
20160294779 Yeakley et al. Oct 2016 A1
20160306769 Kohtz et al. Oct 2016 A1
20160314276 Sewell et al. Oct 2016 A1
20160314294 Kubler et al. Oct 2016 A1
20160323310 Todeschini et al. Nov 2016 A1
20160325677 Fitch et al. Nov 2016 A1
20160327614 Young et al. Nov 2016 A1
20160327930 Charpentier et al. Nov 2016 A1
20160328762 Pape Nov 2016 A1
20160330218 Hussey et al. Nov 2016 A1
20160343163 Venkatesha et al. Nov 2016 A1
20160343176 Ackley Nov 2016 A1
20160364914 Todeschini Dec 2016 A1
20160370220 Ackley et al. Dec 2016 A1
20160372282 Bandringa Dec 2016 A1
20160373847 Vargo et al. Dec 2016 A1
20160377414 Thuries et al. Dec 2016 A1
20160377417 Jovanovski et al. Dec 2016 A1
20170010141 Ackley Jan 2017 A1
20170010328 Mullen et al. Jan 2017 A1
20170010780 Waldron, Jr. et al. Jan 2017 A1
20170016714 Laffargue et al. Jan 2017 A1
20170018094 Todeschini Jan 2017 A1
20170046603 Lee et al. Feb 2017 A1
20170047864 Stang et al. Feb 2017 A1
20170053146 Liu et al. Feb 2017 A1
20170053147 Geramine et al. Feb 2017 A1
20170053647 Nichols et al. Feb 2017 A1
20170055606 Xu et al. Mar 2017 A1
20170060316 Larson Mar 2017 A1
20170061961 Nichols et al. Mar 2017 A1
20170064634 Van Horn et al. Mar 2017 A1
20170083730 Feng et al. Mar 2017 A1
20170091502 Furlong et al. Mar 2017 A1
20170091706 Lloyd et al. Mar 2017 A1
20170091741 Todeschini Mar 2017 A1
20170091904 Ventress Mar 2017 A1
20170092908 Chaney Mar 2017 A1
20170094238 Germaine et al. Mar 2017 A1
20170098947 Wolski Apr 2017 A1
20170100949 Celinder et al. Apr 2017 A1
20170108838 Todeschini et al. Apr 2017 A1
20170108895 Chamberlin et al. Apr 2017 A1
20170118355 Wong et al. Apr 2017 A1
20170123598 Phan et al. May 2017 A1
20170124369 Rueblinger et al. May 2017 A1
20170124396 Todeschini et al. May 2017 A1
20170124687 McCloskey et al. May 2017 A1
20170126873 McGary et al. May 2017 A1
20170126904 d'Armancourt et al. May 2017 A1
20170139012 Smith May 2017 A1
20170140329 Bernhardt et al. May 2017 A1
20170140731 Smith May 2017 A1
20170147847 Berggren et al. May 2017 A1
20170150124 Thuries May 2017 A1
20170169198 Nichols Jun 2017 A1
20170171035 Lu et al. Jun 2017 A1
20170171703 Maheswaranathan Jun 2017 A1
20170171803 Maheswaranathan Jun 2017 A1
20170180359 Wolski et al. Jun 2017 A1
20170180577 Nguon et al. Jun 2017 A1
20170181299 Shi et al. Jun 2017 A1
20170190192 Delano et al. Jul 2017 A1
20170193432 Bernhardt Jul 2017 A1
20170193461 Jonas et al. Jul 2017 A1
20170193727 Van Horn et al. Jul 2017 A1
20170199266 Rice et al. Jul 2017 A1
20170200108 Au et al. Jul 2017 A1
20170200275 McCloskey et al. Jul 2017 A1
20200073433 Aune Mar 2020 A1
Foreign Referenced Citations (1)
Number Date Country
2013163789 Nov 2013 WO
Related Publications (1)
Number Date Country
20190113571 A1 Apr 2019 US