A Sensor for the Detection of CO2in Hyperbaric Gaseous Environments.

摘要

The characteristics of the essential components of a Nondispersive Infrared (NDIR) gas sensor for measuring CO2 concentrations in hyperbaric gaseous environments have been studied. The technique used is to subject a known volume of sample gas to a periodic density modulation and to measure the amount of CO2 present by observing the fractional change in a beam of infrared radiation transmitted through that volume. A sensor that uses this technique has been built for use in habitats at pressures up to 600 psia. It measures 8 x 7 x 14 inches and operates directly from 28 volts DC. The sensor's response is not strongly pressure dependent (the maximum deviation from the response at 14.7 psia being only 18% of reading). Neither re-zeroing nor recalibration are necessary since the design inherently maintains both. 0 to 90% response is about 40 seconds for both increasing and decreasing pCO2. (Author)