Flight experimence with recently developed space shuttle orbiter partial pressure of oxygen sensors

摘要

The Sapce Shuttle Orbiter Atmospheric Revitalization Pressure Control System (ARPCS) uses an electrochemical oxygen partial pressure (PPO_2) sensor together with an amplifier to provide continuous monitoring and control signals to maintain desired oxygen concentrations in a two gas cabin atmosphere. The Orbiter uses three PPO_2 sensors, two for oxygen control in the cabin and one for voting logic instrumentation. These sensors are located in the Orbiter crew cabin air recirculating ducts so as to enable accurate measurement of the cabin partial pressure of oxygen. This measurement is critical both to ensure that physiologically acceptable levels of PPO_2 are available for the crew members and to ensure that high levels of PPO_2, at which materials become highly flammable, are not attained in the atmosphere. Due to obsolescence, the need for a replacement sensor was identified.