Tester for a space micro-accelerometer

This paper presents the simulation scheme, the equipment used and the preliminary results of tests on a space micro-accelerometer. The method uses an electronic circuit to simulate a physical proof-mass (the change of capacitances between the cubic proof-mass and its cage is measured during normal operation). This allows us to completely ground-test all electronic circuits of the micro-accelerometer, which is otherwise very difficult to accomplish (the Earth's gravity force is 100,000 times higher than the measurement range of the instrument). Properties of two digital-to-capacitance converter circuits are discussed (±1.5 pF range) as well as their connection to the micro-accelerometer. Finally, preliminary closed loop testing with a simple step function is introduced.