Qualification of MEMS differential pressure sensors in Martian-like environment

This work describes the qualification of MEMS differential pressure sensors to be used in a particle analyzer for Mars 2020. Two different types of sensors have been initially considered MEMS-33A-001D and NPH-8-002.5-GH, in order to select the most suitable in terms of S/N ratio and sensitivity. Sensors have been calibrated at ambient pressure using as reference a water column differential manometers, selected for the unmatchable stability, key property for tests expected to span across many days. The pressure signal has been generated using the water column manometer itself, allowing to reach the full scale of the instruments and by means of a vane pump in low pressure environment where a capacitive manometer has been used as reference. No variation in the sensor sensitivity has been evidenced after exposure to the expected temperature range for the instruments mounted on the platform of the ExoMars Lander. The final selection of the sensor to be flight-qualified has been made on the SNR because both candidates proved to be compatible with the mechanical loads expected during launch and Martian landing and the expected space environment through all mission phases.