LASER DIODE DRIVEN PRESSURE GAUGE

M. Firak

Abstract

The paper presents the prototype of the membrane pressure gauge with optoelectronical conversion. The main parts of the system are polished metal membrane, plastic (PMMA) 2 m long optical fibres, and the box containing optoelectronic components (laser diode module, beam splitter, photodetectors and op. amps). Pressure changes causing membrane displacement modulate the laser beam conducted by incoming optical fibre. Modulated and reflected beam is conducted through the outgoing optical fibre to the optoelectronical assembly where it is converted into the voltage proportional to the pressure. Two different electronic circuits for the compensation of laser diode light beam intensity fluctuation are compared. The calibration characteristic recorded using mercury filled U-tube manometer in the range from 0 to 0.52 × 10⁵ Pa shows accuracy +/- 0.8 % FS.

Keywords

pressure, measurement, reflective fibre-optical sensor

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IMEKO-WC-2000-TC16-P439.pdf

DOI

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IMEKO TC

TC16 - Pressure and Vacuum Measurement

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