AN IMPROVED ELECTROCHEMICAL CARBON DIOXIDE SENSOR.
Abstract
Continued work with an electrochemical carbon dioxide detector has produced a unit that has improved signal stability as well as a considerably shortened response time. The detector configuration incorporates a pH electrode and an Ag-AgCl reference electrode joined by an electrolyte solution composed of tris(hydroxymethyl)aminomethane buffer and including the enzyme carbonic anhydrase as a catalyst. The various factors affecting the response time were investigated and CO2 tension measurements were obtained with a bare glass electrode. Increased electrical stability, as well as simplification of the electronics, was achieved by the incorporation of a field-effect transistor (FET) in the probe assembly of the detector. The conventional high impedance electrometer system normally used with such detectors was replaced and capacitive pickup problems at the input stage of remotely placed signal conditioners were minimized by close physical arrangement of the FET and the detector. Response times of less than 2 seconds for 98% of a step change (14 to 35 mm. Hg PCO2) were obtained. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1967
- Accession Number
- AD0660557
Entities
People
- Charles F. Martin
- J. Ryan Neville
- Robert J. Reyes
Organizations
- United States Air Force School of Aerospace Medicine