A Data Acquisition System Based on DSP for Mechanical Nanoscale Displacement Sensor

• Main Authors: Yong Yu, Qian Wu, Hanyu Sun, Zhengwei Li, Yunjian Ge
• Format: Article
• Language: English
• Published: IFSA Publishing, S.L. 2012-01-01
• Series: Sensors & Transducers
• Subjects: Nanoscale displacement sensor; Weak signal detection; Data acquisition; Digital signal processor.
• Online Access: http://www.sensorsportal.com/HTML/DIGEST/january_2012/P_905.pdf

This paper presents a data acquisition system based on DSP for a mechanical nanoscale displacement sensor where normal strain gauges are utilized. The key challenge of the data acquisition system is that the original signal is very weak. So the data acquisition system should provide large enough amplification ratio and good noise control capability. We use three strategies to solve above problems. First, two devices, an instrumentation amplifier and an analog to digital converter, are used to construct two stage amplification to provide enough amplification ratio. Second, an analog filter and a digital filter are used to eliminate noise. Third, we carefully choose high precision devices in the system. To test the system, we present a series of experiments. The experimental results validate that the system has good performance at weak signal detection. Furthermore, the system has advantages of large amplification ratio, good noise control capability, and good repeatability. Above all, the whole system can achieve the resolution of 3 nm.