What is an essential requirement when calibrating a differential pressure transmitter?

When calibrating a differential pressure transmitter, proper alignment is critical to ensuring accurate readings. The transmitter must be correctly positioned relative to the process connection points to measure the pressure difference reliably. If the alignment is incorrect, it could lead to measurement errors, as the transmitter may not be able to accurately interpret the pressure differentials due to mechanical offsets or improper alignment with the process lines.

Calibration involves adjusting the transmitter to read accurately across its specified range under defined conditions. If the transmitter is not aligned correctly, even the calibrated settings might yield incorrect output, affecting process control and operations. Thus, ensuring that the transmitter is aligned properly is a fundamental part of the calibration process, making this requirement essential for maintaining measurement accuracy.