Use of Damping Solution for Acceleration Measurements in High Vibration Environments

Abstract

In many accelerometer applications, one can be faced with the challenge of making low amplitude, low frequency measurements in the presence of spurious high vibrations. Wideband, undamped accelerometers are commonly used for acceleration measurements in these applications but dynamic range must be sacrificed so as not to risk distortion and amplifier overload, or even damage to the device. A more suitable approach incorporates damping such that high frequency content above the passband of interest is directly mitigated. This paper contrasts and compares the effect of damping on the performance characteristics of piezoresistive MEMS and bonded strain gage accelerometers. It addresses the compromises that have to be made in terms of temperature response, phase delay, and noise for both fluid and gas damping. Also discussed are the inherent limitations of electronic filtering as an alternate approach for rolling off high frequency noise when using wideband accelerometers. A discussion of specific applications and test results are presented.