Accurate laboratory testing of low-frequency triaxial vibration sensors under various environmental conditions

TL;DR

This paper introduces an environmental testing system capable of evaluating the accuracy of low-frequency triaxial vibration sensors, including MEMS devices, under various temperature conditions simulating earthquake vibrations.

Contribution

It presents a novel testing setup that reproduces long-stroke, low-frequency vibrations across a wide temperature range for sensor accuracy assessment.

Findings

The system achieves approximately 0.23% measurement accuracy.

MEMS accelerometers' earthquake observation accuracy was evaluated.

The setup enables comprehensive environmental testing of vibration sensors.

Abstract

Triaxial vibration sensor are widely used used in various application. Recently, low-cost sensors based on micro electro mechanical system (MEMS) technology are also becoming more widely adopted. However, their measurement accuracy can be affected by environmental factors such as temperature. In this study, we developed an environmental testing system integrated with a triaxial vibration exciter. The system can reproduce long-stroke, low-frequency triaxial vibrations -- such as those caused by huge earthquakes -- under temperatures ranging from $-30~^\circ\mathrm{C}$ to $+80~^\circ\mathrm{C}$. Using this system, the measurement accuracy of vibration sensors can be evaluated under different environmental conditions. The system provides highly accurate reference measurements using a laser interferometer and reference accelerometers that are primarily calibrated within the system. The overall accuracy of the reference vibration measurement is estimated to be approximately 0.23~\%. Based on these reference measurements, we investigated the accuracy of earthquake observations using a MEMS accelerometer as a demonstration. The system configuration and testing procedures are presented in this paper.