Transducer Calibration

APPLICATION NOTES

For best results, transducers should be calibrated or checked with a dead weight before each day of testing. A two point calibration is best. The two point method (suction - discharge) provides for better accuracy in the desired range. Calibration should be done by the dead weight method.

The two point calibration is performed much the same as a zero-span calibration. Instead of using zero you expose the transducer to a low pressure which is close to the suction pressure at the station and enter this as your low (zero) pressure in the calibration routine. You then expose the transducer to a deadweight pressure close to that of station discharge and enter that as the span value in the calibration routine. Once the calibration is done, check it against various deadweight pressures to see how it tracks. This should be done for all of the transducers that will be used during testing.

NOTE:

1. It is a good practice to cycle the transducers between zero and discharge pressure several times before starting the calibration process. Also, make sure you chose a steady platform for the deadweight. This will reduce vibration effects and make calibration both easier and more accurate.

2. Shunt calibration is a good "test" of the electronics in a measurement circuit. It does not, however, account for the actual output of the transducer’s bridge under load. For this reason, a shunt calibration can induce significant errors in a pressure measurement. A shunt calibration is not recommended when data accuracy is important.

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