The Sokken model PGT-500 is a pressure calibration system with generating square wave pressure for the dynamic type transducers and it can be replaced to a conventional hydraulic type dead weight pressure testers. The output from the dynamic type transducers are normally in decay with time for static pressure due to its theoretical configuration and a special skill and a lot of time was required for the precise calibration and less safety for operator to handle a heavy weight of 50kgs.The PGT-500 has several merits to save labor, time and keep safety for operators without handling heavy weights. The correct results are provided within a few minutes only fitting a transducer to the system and to operate a user interface by the operator.
- Precise calibration result is obtained for dynamic type transducers by applying dynamic square wave pressure.
- Only fitting a transducer and programmed operation by the user interface.
- Insulation resistance and low frequency response can be monitored
- Max. 8 transducers can be calibrated simultaneously.
- Safe operation without handling heavy weights for a hydraulic dead weight tester.
|Pressure generating mode||gauge pressure|
|Pressure range||1 to 20 MPa|
|Generating frequency||0.01 to 5Hz|
|Programmed operation||Applying the pressure every 20% of full scale|
|Calibration accuracy||±0.1％ of F.S.|
|Power supply||100V AC ±10％, 1ｋVA|
- Pressure calibration for dynamic type transducers
Charge amplifier SCH-101
The most important data for developing IC engines are to measure the in-cylinder pressure to calculate IMEP (Indicate Mean Effective Pressure), ROHR (Rate of Heat Release) and to analyze knocking.
The most typical pressure transducer to measure in-cylinder pressure for IC engine is called piezoelectric transducers which is utilizing piezoelectric effect. The merits for this pressure transducers are a wide temperature dynamic range, frequency response, small dimensions and easy installation to engines and of course a wide pressure dynamic range but there are some demerits on its DC characteristics, the difficulty of the calibration and it is very affected by the ambient humidity so that the special skill and many hours are required to calibrate them precisely.
Sokken model PGT-500 calibration system uses square wave pressure to calibrate these transducers instead of the conventional hydraulic type dead weight pressure testers. The output from these transducers become small with time for applying static pressure as these transducers are configured theoretically with capacitor then the special skills were required to calibrate the transducers precisely.The PGT-500 is a system to apply the square wave pressure of 2 to 20 MPa repeatedly with 0.1 MHz to both a target transducer and an accurate reference pressure gauge with +/- 0.1% of accuracy and comparing the outputs then analyze the accuracy of those results by computer.
A part of the system is shown in Figure 1. The hydraulic square wave pressure is generated by compressed air using a precise pressure regulator then the air pressure is converted to accurate hydraulic pressure.The accurate hydraulic pressure is generated by switching on and off an ultra high speed solenoid valve mutually for atmospheric pressure and hydraulic pressure as square wave pressure traces. The pressure generated above is simultaneously added to both a target pressure transducer and a reference pressure gauge then comparing the outputs by the computer to analyze the accuracy.
A typical result is shown in Figure 2. The model PGT-500 brings its great ability to calibrate the linearity tests to apply the pressure every 20% of full scale and can make the accurate repeatability test by applying the several fixed calibration pressure with very short time. Also the system has the capability to calibrate the dynamic type transducers in order to apply square wave pressure and can analyze the time constant and insulation resistance by observing the output trace for a lapse of time.
Figure 1, Square wave pressure generator block
Figure 2, Calibration results