DOI QR코드

DOI QR Code

Implementation of Capacitance Measurement Equipment for Fault Diagnosis of Multi-channel Ultrasonic Probe

다중채널 초음파 프로브 고장진단을 위한 커패시턴스 측정 장치 구현

  • Received : 2015.09.29
  • Accepted : 2015.11.06
  • Published : 2016.01.31

Abstract

In this paper, we propose the method to measure the capacitances using not LCR meter but capacitance to voltage(C/V) conversion. And we design the analog MUX circuits that convert 192 channels to 6 MUX channels in order to implement the diagnosis of multi-channel ultrasonic probe. This paper derives the conversion function that converts the digital voltage of each MUX channel to the capacitance using the least squares method because the circuit characteristics that convert the voltage of each MUX channel to the capacitance are different. The developed prototype illustrates the performance test results that the measure times are measured by within 4sec and the measure error rates of maximum, minimum, and average values are within 5% in terms of the repeated measurements of all 192 channels.

Keywords

Capacitance Measurement;Fault Diagnosis of Ultrasonic Probe;LCR Meter

References

  1. Greg Amorese, "LCR/Impedance Measurement Basics," 1997 Back to Basics Seminar, HEWLETT PACKARD(HP), 1997.
  2. Wei-min Chen, "An application for measurement of waterin-oil percentage based on capacitance to voltage signal convert integrate circuit CAV424," Journal of China Institute of Metrology, pp. 94-96, September 2003.
  3. Manufacturer Specifications: Converter IC for Capacitive Signals-CAV44. Available: http://www.analogmicro.de/en/products/ics/cuconverter/cav444/.
  4. M-K Jeong etal., "The compensation algorithm for localization using the least-squares method in NLOS environment," KICS, Vol.37B, No.04, pp. 309-316, April 2012.
  5. Xianming Xiong, "The design of film thickness measure system based on capacitance sensor," 2010 International Conference on Intelligent Computing and Integrated Systems (ICISS), pp. 334-336, 2010.
  6. TMS320F28335 Floating-Point 32bit Micro-controller Data Manual, SPRS439M, Texas Instruments, August 2012. Available: http://www.ti.com.
  7. Hardware Design Guidelines for TMS320F28xx and TMS320F28xxx DSCs, SPRAAS1C, June 2015. Available: http://www.ti.com.
  8. Programming TMS320x28xx and 28xxx Peripherals in C/C++, SPRAA85D, January 2013. Available: http://www.ti.com.
  9. TMS320x2833x Analog-to-Digital Converter (ADC) Module, SSPRU812A, October 2007. Available: http://www.ti.com.