Claims
- 1. A method for measuring low levels of carbon dioxide in a water sample comprising the steps of:
- passing a sample through a cation exchange resin;
- passing the sample through a first membrane separator where said first membrane separator has a first compartment for receiving the sample and second compartment separated by a membrane that allows for an exchange of ions between the compartments, said second compartment supplies a weak base which ions cross the membrane to neutralize any strong acid in the sample in the first compartment and will leave unreacted carbonic acid in the sample;
- taking a first conductivity measurement of the sample exiting from the first compartment of the first membrane separator;
- passing said sample from the first compartment of the first membrane separator to a second membrane separator where said second membrane separator has a first compartment for receiving the sample and a second compartment separated by a membrane that allows for an exchange of ions between the compartments, said second compartment supplies a strong base which ions cross the membrane to convert the carbonic acid in the sample stream to a carbonate salt; taking a second conductivity measurement of the sample exiting from the first compartment of the second membrane separator;
- comparing the first and second conductivity measurements for a change in the conductivity; and
- determining the carbon dioxide content of the sample from any change in conductivity.
- 2. A method as recited in claim 1, further comprising the step of measuring conductivity of the sample after it has passed through the cation exchange resin to provide a cation conductivity measurement for the sample.
- 3. A method as recited in claim 2, further comprising the step of measuring conductivity of the sample prior to passing it through the cation exchange resin to provide a specific conductivity measurement for an untreated sample.
Parent Case Info
This is a division of application Ser. No. 07/499,142 filed Mar. 26, 1990 now U.S. Pat. No. 5,068,090.
US Referenced Citations (4)
Divisions (1)
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Number |
Date |
Country |
Parent |
499142 |
Mar 1990 |
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