title: Ultrasonic detector for high precision measurements of carbon dioxide.
abstract: A new instrument for monitoring atmospheric CO(2) has been developed based on the measurement of the speed of sound in air. The instrument uses a selective scrubber to yield highly precise and accurate measurements of CO(2) mixing ratios at ambient concentrations. The instrument has a precision of 0.3 ppmv (1σ) with a signal that is independent of pressure and requires a flow rate of only 30 mL/min. Laboratory measurements of atmospheric CO(2) showed excellent agreement with values obtained by nondispersive infrared absorption. The instrument has the advantage of collecting continuous, high-precision data every 25 s and can be modified for vertical profiling studies using kites, balloons, or light aircraft for the purpose of measuring landscape-scale fluxes.
authors.affiliation: 2B Technologies, Inc., 2100 Central Ave., Suite 105, Boulder, Colorado 80301, USA.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Andersen
authors.forename: Craig J
authors.initials: CJ
authors.lastname: Williford
authors.forename: Donald E
authors.initials: DE
authors.lastname: David
authors.forename: John W
authors.initials: JW
authors.lastname: Birks