Equipment calibration

In recent years, technology has rapidly advanced beyond all expectations. When purchasing electrical test equipment, the majority of individuals and businesses will opt for the top or ‘leading’ brand – and expect them to be 100% accurate, all of the time. Certainly, as a collective, investment in equipment is growing year on year, and to this end, the process of calibration is becoming an essential and necessary endeavor.

Many people may wonder what calibration is, and how it helps – it is often assumed that electronic equipment that does not involve meter movement will not require calibration, as there are no meter movements to go out of balance. However, they do not take into consideration any event that may render a piece of equipment less than accurate – or even worse, unsafe for use. Calibration can be even more essential if you are working to extremely tight quality control systems, where accurate measurements are essential to ensure correct operation and adherence to safety procedures.

It’s a common mistake to call a comparison check of two meters a “calibration” if the two meters give the same reading. Rather than being a calibration, this is just a simple field check. After all, such a process can indicate that there is a problem, but it can’t tell you which meter actually has the problem. Likewise, if both meters are showing as out of calibration by the exact same amount and direction, a field test will not indicate a problem at all. Your equipment could be severely compromised, and you simply won’t find out about it.

The only way to effectively check for the correct calibration of equipment is to compare the ‘test’ equipment against set standards - using a number of measurement scales. The standards used ensure that the equipment under test passes a set accuracy test. So, calibration is essentially the comparison of a piece of equipment, against a standard, to confirm its performance levels.

The process of ‘correction’ is normally used during calibration. When you send a piece of equipment in for testing, you will generally agree for it to be repaired if it is “out of cal.” This means that, if any equipment is incorrectly balanced, it will be brought back into calibration. In the majority of cases, you will receive a report indicating how far out of calibration the equipment was before, and its measurements post-correction. And what are the causes of electrical equipment being “out of cal”? There are a number of reasons, not least being the natural shifting of major components over time (i.e. input dividers, voltage references). Accidents also account for a number of problems with equipment calibration, for example; if measurement devices are dropped and damaged, they may incur major calibration errors.

Many people will continue to use equipment, such as current clamps, after they have been damaged. This can have a detrimental effect on any business where accuracy is key, and to this end, ongoing equipment calibration will ensure that any problems are spotted and corrected.