Development Of A Pisston Pressure Gauge Based On Laser Measurement

As one of the most important standard instruments for pressure measurement,piston pressure gauge is an instrument with high precision, high repeatability and high reliability on the basis of the Pascal's Law and the theory of hydrostatics equilibrium. It plays an important role in practical precise measurement and value transferring. Measure the piston head's position,the locus of the piston's movement and the piston's speed has important significance for the calibration of piston pressure gauges, which directly influences the accuracy and efficiency of the calibration. The commonly used measuring method in China is based on positioning with projection by lamp light, which has many drawbacks. Firstly, the boundary of the projection head is ambiguous and the movement locus is unclear. Additionally, the speed measurement of the piston head mainly relies on dial indicator and chronograph, which is a kind of contact measurement with the piston in a rotation status under measuring, resulting in remarkable fluctuations in the readout values. Moreover, above measurement relies on artificial operation,which not only has subjective influences from the operator but also shows very low efficiency.This thesis focuses on the research and development of a novel piston pressure gauge based on the laser triangulation principle, which can realize precise measurement of the position and movement speed of the piston. The basic principle of the device is to perform measurement of piston's position and movement locus with two high-precision laser ranging sensors. The analog signal from the sensor is converted into digital signal and fed to a STM32 microprocessor, which sends the processed data to a host computer (a touch-type industrial computer ) through a serial interface. The host computer then uses a graphic user interface (GUI)to display the displacement and the movement locus of the piston on a LCD monitor, and it can also realize the automatic measurement according to the requirements in the National Calibration Standard for Piston Pressure Gauge (JJG59-2007).The instrument adopts 2 high-precision Panasonic HG-C1100 laser ranging sensors, which have a measuring range of 100 mm±35 mm with an accuracy better than 0.02 mm. The senor...