| Popis: |
Three prototype Analox hyperbaric analyzers (model SUB MK II P-S), modified by the manufacturer from a commercially available model designed for submarine escape situations, were evaluated as devices suitable for monitoring O2 and CO2 under pressure during Dry Deck Shelter (DDS) operations. Analyzers were tested in two locations in the laboratory: (1) on the laboratory bench at ambient pressure. and (2) inside a temperature-controlled hyperbaric chamber at pressures less than or equal 6 atmospheres absolute. The instruments were easy to use in the laboratory and provided no major operating problems during the test period. At 25 degrees C, they met desired accuracy limits for both O2 and CO2. However both cold and hot exposures caused O2 and CO2 readings to exceed these limits. The instruments also operated with a single set of new batteries for a sufficient time (6 hours daily over a multiday period) and over a range of ambient temperatures to support DDS operations. Following deliberate immersion, clearing water from the instruments' inlets and returning them to operators in the laboratory was often difficult, doing so in the field would be even more challenging. Before any decision can be made about advancing these analyzers to field-testing, the manufacturer needs to make the following changes to the instruments, and the laboratory needs to verify their acceptability with additional testing: (1) improving the compensation of gas measurements for changes in ambient temperature, and (2) redesigning the gas inlet to facilitate the clearing of water following accidental immersions. |
