Patent ID: 9459223
Filing Date: 2016-10-04
CPC Classification: G01N

Claim Text:
1. A method for chemical vapor identification of an unknown hydrocarbon analyte vapor using swelling-based sensors, comprising the steps of: providing an apparatus for identifying the unknown hydrocarbon analyte vapor, the apparatus comprising: maintaining the unknown hydrocarbon analyte vapor in the first chamber having the first chemiresistor disposed therein until the first chemiresistor is saturated with the unknown hydrocarbon analyte vapor at a first temperature, wherein the first temperature is approximately 20° C.; maintaining the unknown hydrocarbon analyte vapor in the second chamber having the second chemiresistor disposed therein until the second chemiresistor is saturated with the unknown hydrocarbon analyte vapor while maintaining the second chamber at a second temperature colder than the first temperature; calculating the sensitivity of the first chemiresistor and the second chemiresistor simultaneously at the different temperatures; calculating the enthalpy of vaporization of the unknown hydrocarbon analyte from the sensitivities of the first and second chemiresistors and the first and second resistors; comparing the calculated enthalpy of vaporization of the unknown hydrocarbon analyte with published literature values of the enthalpy of vaporization of known hydrocarbon compounds; and identifying the analyte hydrocarbon vapor as a known hydrocarbon compound when the calculated and published enthalpies of vaporization are substantially the same.