What compromises electrical test equipment accuracy?

Industries that use electrical equipment depend on accurate test instruments for safety, quality, and profitability. If an electrical test device’s accuracy is compromised, a false reading can lead to product defects, equipment failures, reputational damage, and even injury or death.

But the risks that come from inaccurate electrical test equipment can be managed. Knowing why test devices lose accuracy and what can be done to prevent this, and with regular calibration, instruments will perform within tolerances.

Why calibrate electrical testing equipment?

All testing equipment suffers from measurement drift. This means an instrument’s accuracy is reduced over time. Regular calibration is required, as leaving too long a gap results in measurement drift.

If left uncalibrated for too long, the device’s readings will move out of tolerance. This can have serious consequences, such as:

• Potentially life-threatening safety risks arising from faulty electrical equipment tested by inaccurate test devices
• Manufacturing defects resulting in faulty product batches
• Product recalls causing reputational and financial damage
• Equipment failures occur because inaccurate condition monitoring equipment gives false readings

Product quality depends on accurate electrical measurement equipment, and this needs regular calibration checks. If the equipment’s measurement values are small, then even a tiny amount of measurement drift can cause a major problem.

What causes measurement drift in electrical testing equipment?

Over time, during regular use and while in storage, measurement drift compromises electrical test equipment accuracy. Exactly how the equipment is used and stored can make the drift worse. For example:

• Environmental conditions affect the instrument during use and in storage. High humidity or extreme dryness, exposure to electromagnetic interference (EMI) and strong magnetic fields can all result in measurement drift. EMI and magnetic fields can cause permanent damage to sensitive electrical test devices.
• Rough handling is a common cause of measurement drift. Physical shocks, drops and knocks can damage sensitive components, sensors and meters. After a drop, the equipment may appear to work, but may no longer be accurate. Recalibration is needed to be sure.
• Out of range use exposes equipment to loads beyond its original specifications. Testing a 690V power supply using a voltmeter that is rated at 600V will cause drift resulting from the harmful electrical stresses on the device’s measurement circuits.

How to maintain electrical test equipment accuracy

Straightforward steps to minimise the impact of these factors include:

• Correct storage and transportation help mitigate the impact of rough handling and environmental impact. Basic steps such as using shockproof, waterproof, Radio Frequency Interference shielded equipment cases eliminates many causes of measurement drift.
• Making sure measurement devices are fit for purpose, and not out of range. If testing for specific RF emissions, the test device must be specified to measure the correct frequency ranges.

Even when protected, electrical test instruments require regular calibration, according to the manufacturer’s recommended schedule.

Keeping your electrical test equipment accurate

Our technicians have extensive experience with electrical test equipment used in industries such as automotive, defence and aerospace, where tiny deviations in readings can have catastrophic consequences. Accurate electrical calibration of devices measuring voltage, current, resistance, capacitance, inductance and power is vital.

Our calibration solutions as UKAS-accredited are underpinned by our ISO 9001 quality management system. These standards cover both on-site calibration at your site and in our calibration laboratories.

For more information on electrical test equipment calibration strategies, on-site calibration or to find out which of our electrical test equipment calibration services will meet your needs, contact DM Systems & Test.