The present invention relates to an optical digital thermometer (referred to as DT), which belongs to the areas of quantum optics and photonics technology. More particularly, the invention relates to achieving digital processing of optical signal by reducing the transmission speed of a high-speed quantum waves, in this way, accurate measurement of temperature can be implemented.
The present invention is an optical digital thermometer, which is based on the innovation of digital optics: high-speed quantum waves that carry temperature information are slowed down so that individual quantum can be distinguished easily via common electro-optic devices. The said thermometer can replace traditional non-contact thermometers based on Planck's Law of Blackbody Radiation and other theories established by Stefan Boltzmann, Wien, Rayleigh, Hopkins, Planck and other scientists, which describe relationships between temperature and radiation and are problematic in 4 aspects:
Stefan and Boltzmann published their research result on the relationship between thermal radiation and temperature in 1879 and 1884, respectively. The foundations of statistical thermodynamics were laid down in the late 1800s by those such as Maxwell, Boltzmann, Max Plank, Clausius, and Josiah Willard Gibbs. Nobel laureate Wien's displacement law states that the wavelength distribution of thermal radiation from a black body at any temperature has essentially the same shape as the distribution at any other temperature, except that each wavelength is displaced. Rayleigh Jean's Law, published in 1900, stated that radiation energy increases with electromagnetic frequency proportionally, but Rayleigh and Jeans did not realize the logarithmic growth law of energy on frequency. Planck completed his blackbody radiation experiment in 1900, his Law of Blackbody Radiation was published in 1901, Planck's theory made implicit use of the light quantum hypothesis.
They all, in the historical context, have made great contributions in temperature measurement, but in the field of non-contact temperature measurement, use of said theories for quantization correction of non-standard blackbody radiation can not achieve precision measurement. In fact the temperature difference between edge and center of a surface of a standard blackbody calibration furnace is 1-4° C., and because the radiation coefficient of a material is not a constant, as a example, at the same condition, temperature difference of shiny and rough aluminum surfaces measured by traditional non-contact infrared thermometer can be as high as 100° C., temperature measurement in this way leads to a qualitative and vague result, therefore for actuate temperature measurement the said laws must be abandoned.
To this end, based on our long-term experiments and theoretical analysis, the present invention proposes a “distribution and measurement rule of discrete quantum and consecutive quantum energy”, which concludes the following formula:
E=LnT=γh=mb=NB (1)
This formula indicates that at temperature T, where T is Kelvin scale, the spontaneous radiation of energy E can be expressed by the length of the quantum line, which equals the natural logarithm of temperature. When all quantums are aligned in sequence order, thermal radiations emit not only quantum wave, but also electro-magnetic wave, the corresponding quantum line length equals to the wave number of electromagnetic wave N; which equals the product of distances between their basic units (h, b, B). Therefore, the above formula can achieve non-contact temperature measurement of a point, with a variety of different levels of precision, the measurement results have nothing to do with the size of the measured object, the measurement distance, and material properties (the surface emissivity). This is a revolution in temperature measurement technology.
The present invention is an optical digital thermometer. According to the proposed quantum and quantum energy distribution and measurement rule, for an electromagnetic waves with frequency γ and wave number m=1/λ means “quantum”, it is essentially discrete, but quantum energy is consecutive. Photons, electrons, and other basic particles can be unified in the quantum theory, referred as the quantum wave. In the process of information transmitting and receiving, digital technology is identical to quantum technology. Quantum energy is the spacing of adjacent quantums, it is consecutive, on the other hand, quantum and quantum energy have synchronic distributions and in logarithmic order, within the “ordered” limit, the product of quantum number and the quantum energy is the total energy E. Temperature (heat) of a point at the surface of a object and the corresponding wave energy of spontaneous emission (quantum energy) of that point raise with increasing temperature, but the increasing rate is slow down, until saturation is reached, that is to say the “ordered states” ends. This is what we call the logarithmic distribution, it can be mathematically expressed in following formulas:
E=LgT or LnT (2-A)
E=γh=mb=NB (2-B)
Based on these formulas, at temperature T, heat energy equals to wave energy, the length of quantum line equals to the product of quantum number and quantum spacing, it is a orderly arranged straight line, as shown in (2-B), its length can be measured using (2-A) as reference ruler, the scale of the ruler is determined by the base of adapted logarithm, natural logarithm and Kelvin scale are used in (2-A), when converting high-speed quantum wave NB into a low-speed quantum wave mb, selection of proper electronic components is important to have B distinguishable. For temperature T, as long as T>0, Celsius, Fahrenheit, or Kelvin scales can be adapted. For better measurement precision, more quantum numbers within a certain length is desired. In formula (2-B) γ is frequency, h is the distance between adjacent oscillators, m is wave number, b is the spacing between adjacent wave numbers, (it is actually the length of a wave number); temperature T and energy distribution change with N, γ and m, but N has low transmission speed, it can be distinguished by existing optical components, based on these, it is easy to get the distance between the two quantums, or B=LgT/N, or B=LnT/N, where B is enlarged by n. when the true temperature T is found, it should be decreased by n times, as shown in
Based on formulas (1) and (2), non-contact thermometer with varying precision levels can be made. As long as the scale of the ruler has been set as lgT, in order to improve the measurement accuracy, one must increase the code number N to shorten the distance B. With the improved accuracy, the said thermometer can be used as standard calibration instrument to achieve a revolution in temperature measurement technology. As well known, for standard platinum-rhodium thermocouple, the joint-point of two metal lines is the sensitive part of the thermoelectric effect, with the surface temperature measured in the range of 300° C.-1450° C. the measured temperature is correct, because the point temperature measurement is independent of the material property and size, the measurement distance is zero, when the temperature variation is slow and can be treated as quasi-static condition, the measurement accuracy is so high that it can be used as a temperature measurement standard. However, under high temperature and dynamic conditions, thermocouples are not competent, the response is very slow, and a lot of precious metals are consumed, therefore non-contact temperature measurement technology is a demanding technology Using concept of quantum length for temperature measurement is both accurate and convenient, the key technology is to reduce the transmission velocity of quantum wave.
An optical digital thermometer is shown in
Larger effective diameter of spherical lens shown in
For low temperature measurement, another version of optical digital thermometer is designed, as illustrated in
Based on the invention, accurate temperature measurement has been implemented.