Fluke DMM


Bench-grade digital meter

My needs are served half the time by a simple sub $100 DMM. Other times, I need a more complex and reliable meter. The Fluke 87V is that meter for me.

The 87V is more a general-purpose tool than Fluke’s T5, previously reviewed on Cool Tools. The T5 is a compact, limited resolution (only four-digit display) tester. It does not appear capable of measuring many of the things that the 87V can handle. The 87V can measure a much wider range of voltages and currents with greater accuracy. It also has an analog-style bar graph to help show trends, stores max./min. readings and will sound warnings if limits are exceeded. It can answer all the same questions as the T5, except in some cases it would need a probe (the open jaw mechanism for measuring current without breaking the circuit is the T5’s killer feature).

The 87V can also measure temperature (with a probe), frequency (for control circuits) and handles in-line current measurement to 20A. The peak capture will let you see spikes on a signal/control line as short as 250 us. It also has built-in filters for measuring voltages on noisy lines (as with motors).

If you only need to know how many volts or how many amps in a household setting, the T5 is surely sufficient. If you want a bench-grade tool for the homeowner, automotive and/or electronics hobbyist, the 87V is the real deal. For me, most of the time, the application is automotive or motorcycling (ensuring that things are charging and within spec); or that I can confirm the homemade wiring harness is assembled correctly prior to plugging in the $100-plus parts and accidentally cooking them. For more complex things, like servo controls in remote control applications, the duty-cycle measurements the 87V gives help confirm that the servos are in the right position.

I don’t use the frequency feature very much, but temperature measurement is useful in a few applications when debugging cooling problems in equipment, too. When trying to solve a problem with a power supply or load-induced glitch, the max/min hold functionality is great. You can stress and test the circuit and see the min. (or max.) readings after the fact to confirm, or refute, the problem.

The Fluke 87V is the benchmark by which most are measured. Knowing that it can be beat on and abused, yet continues to give me lab-grade results year after year means I just depend on it and stop wondering what is going on. It tells me.

-- Alan Hawrylyshen 09/8/09