Sensor Adjustment
Metrological procedures establish the baseline output of a measurement instrument when the input stimulus is absent. Applying a zero point calibration aligns the output of a sensor to read exactly zero when the measured quantity is zero. This process eliminates any offset error that has developed over time or due to environmental changes.
It is the first step in a complete calibration sequence.
Drift Correction
Environmental factors like temperature, pressure, and aging can cause a sensor’s baseline output to shift. Performing a zero point calibration removes this offset, ensuring that subsequent measurements are accurate across the sensor’s range. This adjustment is particularly important for high-precision gas sensors and pressure transmitters that operate continuously.
It prevents the accumulation of measurement errors over time.
Procedure Execution
The instrument is exposed to a reference condition that represents zero stimulus, such as a vacuum or zero gas. Once the reading has stabilized, the zero point calibration adjusts the internal sensor register to match this reference. This step must be performed under controlled laboratory conditions to avoid introducing new errors.
It is verified using a certified reference standard.
Tolerance Verification
The remaining offset after adjustment must be within the manufacturer’s specified tolerance band to pass the calibration test. This ensures performance.
