Development of a Miniature,Rapid-Response Carbon Dioxide Sensor.

摘要

The Laboratory is developing a miniature carbon dioxide sensor that will accurately detect fluctuations in ambient CO sub 2concentrations of 0.25ppM (v/v). This sensor has a full-scale response of 10Hz and an input power requirement of 3 W. The sensor head,weighing less than 0.5kg,can be held in the palm of the hand. Insensitive to vibration or random acceleration,the sensor is nonthermostated and will operate in noncondensing environments from -20to +40exp 0 C. The principle of measurement is that of the differential absorption of CO sub 2at 3.85and 4.27mu m. The sensor will use a complementary metal oxide semiconductor microprocessor to correct for water vapor effects and density changes in the measurement path,and to display and/or output concentration directly. The microprocessor should also allow accurate calibration utilizing a single calibration gas,while other design factors should eliminate the need for frequent calibrations. Three prototypes of this instrument are currently being fabricated and will be available for optimization and field-testing during the last half of 1978. Efforts are being made to accelerate the test schedule so that technology transfer operations can begin near the end of 1978. This acceleration could result in the sensor being available from a commercial vendor during 1979. (ERA citation 04:014481)