A resonant pressure microsensor capable of self-temperature compensation.

Yinan Li,Jian Chen,Zhenyu Luo,Junbo Wang,Deyong Chen

doi:10.3390/s150510048

Abstract

Resonant pressure microsensors are widely used in the fields of aerospace exploration and atmospheric pressure monitoring due to their advantages of quasi-digital output and long-term stability, which, however, requires the use of additional temperature sensors for temperature compensation. This paper presents a resonant pressure microsensor capable of self-temperature compensation without the need for additional temperature sensors. Two doubly-clamped “H” type resonant beams were arranged on the pressure diaphragm, which functions as a differential output in response to pressure changes. Based on calibration of a group of intrinsic resonant frequencies at different pressure and temperature values, the functions with inputs of two resonant frequencies and outputs of temperature and pressure under measurement were obtained and thus the disturbance of temperature variations on resonant frequency shifts was properly addressed. Before compensation, the maximal errors of the measured pressure values were over 1.5% while after compensation, the errors were less than 0.01% of the full pressure scale (temperature range of −40 °C to 70 °C and pressure range of 50 kPa to 110 kPa).

Highlights

Pressure microsensors are widely used in the fields of aerospace exploration and atmospheric pressure monitoring due to their advantages of small size, high resolution and low cost [1]
Based on their detection mechanism, these microsensors can be classified into capacitive pressure microsensors [2,3], piezoresistive pressure microsensors [4,5], piezoelectric pressure microsensors [6,7] and resonant pressure microsensors [8]
The compensation error was less than ±0.01% of full pressure scale (50 kPa~110 kPa) in the full temperature range (−40 °C~70 °C)

Summary

Introduction

Pressure microsensors are widely used in the fields of aerospace exploration and atmospheric pressure monitoring due to their advantages of small size, high resolution and low cost [1]. Our previous work [20] proposed a differential output pressure microsensor with double “H” type resonators Based on this double-resonator structure, a self-temperature compensation approach was put forward in this study, which reported an accuracy of ±0.01% over the full pressure and temperature scale (temperature range of −40 °C to 70 °C and pressure range of 50 kPa to 110 kPa). In this method, the compensation can be realized only after acquiring the frequencies of two resonators without the need of additional temperature sensors

Device Structure

The Self-Temperature Compensation Algorithm

Calibration Point Selection Optimization

Compensation Results and Analysis

Conclusions