Meter Calibration
Hanover Testing Labs provides precision calibration services for the electric utility industry. Our accredited laboratory tests digital and analog voltmeters, phasing meters, wireless phasing meters, ammeters, non-contact live line testers, probe high voltage meters and wireless temperature probes.
The Hanover Testing Labs state-of-the-art facility gives us the ability to test both AC and DC voltage calibrators to confirm accuracy. Our IBEW trained technical team are experts providing consistency, accuracy and quality.
The calibration process begins with the design of the meter that needs to be calibrated. The design of the meter needs to be able to "hold a calibration" through its calibration interval. In other words, the meter has to be capable of measurements that are "within engineering tolerance" when used within the stated environmental conditions over some reasonable period of time.
Having a design with these characteristics increases the likelihood of the actual meters performing as expected. Basically, the purpose of calibration is for maintaining the quality of measurement as well as to ensure the proper working of particular instrument.
Test probes and Non-Contact High Voltage Detectors vary from a Task-Off probe to simple voltage probes that connect directly to AC or DC power lines and couple interference into the measurement receiver, however the coupler reduces the value by 20 dB to 30 dB, based on the device.
Our process follows the requirements of ANSI C63.5, resulting in very granular data collection throughout the frequency spectrum. While this procedure may produce many data points, we will reduce the coupling factor data to a manageable value while maintaining an accuracy of 0.1 dB with respect to the full breath of data.
The most common calibration interval is yearly. Some specifications may have a different calibration interval, or period in between calibrations. The time in between calibrations can also change depending on time, environment, and use.
Depending on the calibration state of the meter, and the customer’s requirements, there are three different sequences of operation that could be followed. The third sequence is the most common and most valuable for calibration customers.
- Calibration only (no adjustments made).
- Adjustment first; post-adjustment calibration (as left data).
- Pre-adjustment calibration (as found data); adjustment; post-adjustment calibration (as left data).