Electrical instrument safety
“Is it safe?” is a question that anyone working around electricity should ask regularly. Electricity is dangerous; it can shock, burn, or even kill. As such, safety must be the number one priority when working with it. Ultimately, it is the responsibility of the user to ensure that conditions, processes, and equipment provide the highest level of protection possible for themselves and others.
Special clothing, gloves, masks, and boots are among the physical safety tools that can be employed. Detailed procedures outline safety best practices to limit the risk. The physical work area can be arranged in ways that make it safer for the worker.
Test and measurement instruments are also part of the safety equation. They should operate safely in the chosen test environment and intended application, while protecting against foreseeable misuse and unplanned electrical events, like voltage spikes. But how do you ensure that the test instruments you’re using will provide the highest level of protection?
Most instrument manufacturers are happy to tell you that their products are designed to be safe. It’s rare for suppliers to openly acknowledge areas where additional safety features may have been integrated into a design.
Even when manufacturers make general safety claims, it's important to keep in mind that, as a user of electrical test equipment, safety remains your responsibility. An informed user knows the questions to ask and the standards to look for. You need to get beneath the surface of the word ‘safe’ to reveal the specific details that test instruments should address.
The International Electrotechnical Commission (IEC) standard 61010 covers safety requirements for electrical equipment for measurement, control, and laboratory use. It includes requirements for testing and measuring circuits and for instruments. IEC 61010 is the basis for instrument safety and draws in other standards to support its requirements.
A critical aspect of the safety standard is the environment where the instrument will be used. The following are some concepts included in and beyond IEC 61010 that you should have knowledge of:
- Measurement category rating
- Ingress protection rating
- Pollution degree
- The Comparative Tracking Index
- Test lead design
Understand these topics and ask manufacturers appropriate questions relative to them. You need to demand complete answers and refuse to settle for weak responses. A life may depend on the instrument design, so if you’re asked “is it safe?”, you can be confident in your answer.