Testing Standard
An international testing protocol that defines the methods and procedures for evaluating the performance of process control instruments under static and dynamic conditions ensures consistency across manufacturing laboratories. Compliance with iec 61298 2 establishes the baseline for testing how various environmental and electrical variables affect sensor accuracy. This document guides test engineers in structuring trials for pressure, temperature, and flow transmitters.
By following these structured procedures, manufacturers can generate comparable performance certificates.
Influence Quantity
Environmental and operational variations can alter the behavior of a measurement device during field operation. Under the guidelines of iec 61298 2, testers systematically vary influence quantities such as power supply voltage, ambient temperature, and vibration to measure the resulting output deviation. Each test isolates a single variable while holding others constant to determine individual error contributions.
This systematic isolation allows engineers to calculate the individual sensitivity coefficients of the device under test.
Calibration Verification
Reference instruments used during the evaluation must possess a certified accuracy that is several times higher than that of the device being evaluated. The iec 61298 2 standard requires that calibration systems have traceable accuracy to national measurement standards. During the test, the input is ramped up and down through a series of specific setpoints to capture hysteresis and repeatability errors.
These calibration steps are performed under reference conditions before and after the influence tests to verify that no permanent offset occurred.
Evaluation Boundary
The applicability of the testing procedures is limited to specific operating limits defined by the manufacturer or the standard. If a transmitter is subjected to conditions beyond these specified boundaries, the test results may not accurately represent standard performance.
