Testing Framework
International evaluation standards establish uniform procedures for assessing the performance of industrial process transmitters. Adhering to IEC 60770-1 ensures that manufacturers and testing laboratories use the same methods to evaluate the accuracy and repeatability of pressure or temperature sensors. This uniformity allows direct comparison between different sensor models.
Standardized Protocol
The document defines specific reference conditions, such as ambient temperature and supply voltage, under which all baseline measurements must be performed. It outlines methods for determining linearity and hysteresis using a series of stepped calibration inputs across the full span of the instrument. Testing must be repeated multiple times to calculate the statistically valid repeatability of the sensor.
By defining these steps, the standard removes user bias from the performance data and ensures that the calibration tests are easily repeatable across different test labs.
Operating Deviation
Varying environmental factors, such as electromagnetic interference and ambient temperature swings, can degrade transmitter performance under field conditions. The standard specifies tests to evaluate how much the transmitter deviates from its reference performance when exposed to these individual stress factors. If a sensor exhibits high sensitivity to temperature drift during these trials, its suitability for outdoor installations is compromised.
Compliance Assessment
Certifying agencies verify that a transmitter meets its stated specification sheet by conducting the full battery of standard tests. The resulting evaluation report lists the measured errors next to the manufacturer claims to confirm compliance. This certification process provides system integrators with trusted performance data for safety critical process control loops.
