PNEUMATISCHER PARTIALDRUCKSENSOR.

摘要

A flueric partial pressure sensor (10) includes a flueric bridge sensor (10a) having two bridge legs (11, 12) adapted for sensing a reference-gas and a sample-gas. A linear resistor (14, 15) and an orifice resistor (16, 17) are incorporated in each leg and arranged to cause asymmetric flow rates therethrough. Inlets to the two bridge legs are subject to a datum pressure within a datum pressure chamber (38) so that a change of datum pressure automatically changes control signals output by the sensor. The partial pressure sensor is disclosed in combination with a molecular sieve type gas concentration system (24) in an on-board oxygen enrichment of air system for an aircraft and enables the oxygen concentration in oxygen enriched air delivered by the system to be appropriate to breathing requirement at an altitude intermediate aircraft cabin and ambient atmospheric pressures.