Safety Certification Standards and Safe Use of Digital Multimeters
When you see symbols like UL, CSA, TUV, etc. or read words like "Designed to meet the requirements of ....," you often think of independent testing and certification organisations. you tend to think of independent testing and certification organisations. How can you prove that your digital multimeter meets CATIII or CATII (see CATI, CATII or CATIII standards and definitions article)? It is quite possible that the manufacturer himself thinks that his meter meets CATIII or CATII without any independent certification. The International Electrotechnical Commission (IEC) only develops and recommends its standards, but is not responsible for enforcing them. Only when a product has been tested to fully meet the standards of an independent certification body, such as UL, CSA, TUV and other certification bodies can be marked on the instrument, such as UL3111, is based on the IEC1010 standard. In the mixed instrument market, independent testing and certification is not the best, but may be the most direct way to identify.
Safe use of a digital multimeter starts with choosing the right digital multimeter for the application and meeting the application environment. Once you've chosen the right digital multimeter, you'll want to use it in accordance with its normal application. The International Electrotechnical Association (IEEA) has set new standards for working under power systems. Verify that the digital multimeter you are using meets the IEC standard and that its voltage rating meets the requirements for field applications. For example, if measuring a 480V power disc, your digital multimeter will have to meet the CATIII/600V standard, which means that the input circuitry of this meter is designed to withstand transients in this application without harming the user. Choosing a digital multimeter labelled UL, CSA, CDE, TUV means that the meter not only meets IEC standards, but has also been independently certified and tested to meet the independent testing organisation's own standards.
