Automatic pressure calibration system for pressure sensors

Pressure sensors are devices that sense the pressure and convert it into electrical signal whose magnitude depends upon the pressure applied. These sensors are employed in ground tests during engine development for aircrafts. The output (electrical signal) provided by these sensors form part of input to airworthiness checks of the aircraft. Hence, it needs to be re-verified or re-calibrated to evaluate its performance at specified or regular intervals of measurement and control. Towards this objective, sensor calibrations are performed using comparison method at Calibration Laboratory. Manual pressure calibration using hand pumps is a tiresome and time consuming process for metrologists. Metrologists find it very difficult to generate different steps and monitor pressure. The efforts will be further magnified in a laboratory environment where there will be a need to calibrate more numbers of pressure sensors on a regular basis. The situation further gets complicated with the different types and ranges of outputs from pressure sensors. The setup consists of a Precision Pressure Controller, Data Acquisition/switch unit and a Pressure manifold. An effort is made to exploit the capabilities of these instruments by automating the pressure calibration process by developing an automation software using NI LabVIEW.