Digital multimeters are designed to assist users to carry out, from simple to highly complex test and measurement functions on the bench or increasingly, remotely in the field. From time to time, users should test meters and other equipment in the field, and by paying attention to the following quick steps, could help ensure the safety and efficiency of the meter.
- Use common sense. Before beginning, take a closer look at the equipment and accessories. Does it look shabby and badly worn? If so, perhaps the unit is beyond functional and shouldn’t safely be used.
- Inspect leads. Before using test leads, perform an inspection to ensure the leads can safely and accurately conduct electricity for the job at hand. Be sure the leads have:
- Shrouded connectors
- Finger guards
- CAT ratings that equal or exceed those of the meter
- Double insulation
- Minimum exposed metal on the probe tips
- Continuity testing. Use the meters own continuity testing function to check for internal breaks. Check test lead resistance by:
- Inserting leads in V/Ω and COM inputs
- Selecting Ω, touching probe tips and being sure the leads are 0.1 – 0.3Ω
- Choose accessories that are suitable for industrial work, and check for abrasions and other damage that eventually occur with use. This way, users will never have to worry about the failure of a test lead or probe—or the consequences thereof.
- Inspect test lead insulation.
- Check and ensure that the insulation is not nicked or cracked. With age the insulation material—whether PVC or silicone—can become dried out, brittle and susceptible to cracking.
- A visual inspection will often show any part of the leads that has this problem.
- Ensure that there are no signs of gaps or cracks at the junction between the insulated wire and the molded banana plugs or probes at each end.
- Verify correct voltage rating. Verify that the meter and accessories are appropriately rated and designed for the system and equipment to which they will be connected.
- Check for the IEC rating (e.g., CAT III or CAT IV) on the tester, and only purchase leads and other accessories that meet or exceed that rating.
Safety checking equipment in the field can reduce hazards and ensure that equipment is safely functional. Whether the equipment is a voltage tester or a digital multimeter, users could benefit greatly by carrying out a quick safety scan before commencing work.
PICTURE CAPTION: CAT ratings can be found between the input jacks on most tools
Comtest provides test and measurement, communications, process control, equipment, solutions and specialised systems from world leading manufacturers, like Fluke, to the southern African market. Fluke is the world leader in the manufacture, distribution and service of electronic test tools and software. For more information about seminars, demos or to locate the nearest dealer, please contact the Comtest sales team on 010 595 1821 or firstname.lastname@example.org