Research On Precise Gas-electric Measuring System

Pneumatic history measurement technology has been more than70years, although in recent years the electric instrument, inductance measuring instrument, but due to the advantage of pneumatic measuring instrument is unique, it is still widely applied in some fields.Pneumatic measurement is the use of air flow characteristic, a change amount conversion variable geometry will be measured workpiece into pressure, precision measuring instruments and read out the geometry parameter of the measured workpiece in pressure indicator. Due to the use of gas as medium, so the method has the characteristics of non-contact measurement. The use of pneumatic measuring method, measuring device and the measured not in contact with the workpiece, so there is no measurement of force, thus making the mechanical processing industries are still widely used. In the measurement of pore size, special process parameters of roundness, pneumatic measurement technology compared with other measurement techniques are compared, with incomparable advantages.This paper study on measurement technology of gas from the whole aspect angle.The first principle of the measurement are analyzed in detail, the design method of measuring circuit combined several typical, analyzes its advantages and disadvantages, put forward the improvement scheme. This scheme adopts the differential pressure gas, gas and electricity conversion device is an adjustable throttle valve with special structure, principle of the annular ejector, design of the actual structure, and using the method of computational fluid dynamics simulation analysis of rationality of design, theoretically proves the feasibility of the scheme.In terms of hardware, in addition to processing outlet power converters and build gas road, also made the electronic measuring device design and. Each measuring instrument can multichannel measurement, no channels are independent units of measurement. The measuring unit consists of embedded processor, AD converter, communication module and so on. Measuring instrument is composed of ARM processor, external memory, touch screen TFT display module etc.In the aspect of software, according to the measurement requirements, design the graphical user interface (GUI), the application of embedded real-time operating system p. C/OSII, greatly simplifies the task of design.Finally, the design of device use, based on the analysis of the aerodynamic characteristic curve measurement. Data show that, by adopting the structure can improve the measuring instrument, measuring range greatly, extends the linear interval measurement instrument.