Investigation of the Feasibility of an NDIR Technique to Detect CO2 in a Hyperbaric Gaseous Environment.
ANDROS INC BERKELEY CALIF
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A nondispersive infrared NDIR technique for monitoring CO2 has been thoroughly evaluated to determine its suitability for use in a hyperbaric environment. 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. Experimental results indicate the validity of the technique for total pressures up to 1200 psia, in He containing up to 15 psia of O2N2, and CO2 partial pressures up to 30 mm. A single point calibration with CO2 span gas at any pressure should be necessary only infrequently. Response times of the order of a few seconds are possible. It is anticipated that this technique can be used in a CO2 alarm sensor for inclusion in a saturation divers breathing apparatus, as well as in hyperbaric habitats and Personnel Transfer Capsules. Modified author abstract
- Atomic and Molecular Physics and Spectroscopy