Calibration of pressure measurement instruments – method

Calibrated instruments

The laboratory performs calibrations of electronic instruments, including:

• relative and differential pressure gauges and transducers,
• absolute pressure gauges and transducers.

Calibration method

Depending on the expected accuracy of the instrument, the adopted measurement procedures outline 3 calibration methods:

1. The based method, which should be used for instruments with an expected expanded uncertainty (k = 2) of measurement U > 0.2% FS. In this method, calibration is conducted once at 6 pressure points for increasing and decreasing pressures. Zero error, repeatability, and transducer hysteresis are determined based on three repeated measurement series at 2 pressure points (typically 0 and 50% FS).
2. The standard method, which should be used for instruments with an expected expanded uncertainty (k = 2) of measurement 0.05% FS < U < 0.2% FS. In this method, calibration is conducted once at 11 pressure points for increasing and decreasing pressures. Zero error, repeatability, and transducer hysteresis are determined based on three repeated measurement series at 4 pressure points (typically 0, 20, 50, and 80% FS).
3. The full method, which should be used for instruments with an expected expanded uncertainty (k = 2) of measurement U < 0.05% FS. In this method, calibration is conducted at 11 pressure points for increasing and decreasing pressures in three measurement series. Zero error, repeatability, and transducer hysteresis are determined separately for each calibration point.

The choice of measurement method according to which the calibration will be conducted is up to the Customer. Upon request, the Laboratory provides assistance in selecting the appropriate calibration method based on the accuracy and application of the measurement instrument intended for calibration.

Calibration in the negative pressure range