Ultrasonic detector for high precision measurements of carbon dioxide.
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.
Andersen
Peter C
PC
2B Technologies, Inc., 2100 Central Ave., Suite 105, Boulder, Colorado 80301, USA.
Williford
Craig J
CJ
David
Donald E
DE
Birks
John W
JW