Why does nobody talk about pin drag on a multimeter until it bites you?

Got a 737 back online last Tuesday, everything tested fine on the bench. Slapped it in, fired up the system, and got intermittent flag 23s all afternoon. Chased my tail for 2 hours before I noticed my meter leads had almost 0.8 ohms of drift from a worn pin on the banana jack. Swapped to a new set of Fluke leads and the issue vanished. 0.8 ohms sounds like nothing but in a 5 volt loop it's everything. Anyone else keep a set of leads dedicated to low resistance checks or am I the only one who learned this the hard way?

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quinnj2429d ago

Wait until you see what a worn shunt does to a calibration sheet. 0.8 ohms in a 5 volt loop sounds like you were already running way too hot on your tolerances, honestly. I keep a set of cheap leads for daily stuff and a Fluke set for anything under 10 ohms, but that's just because I hate redoing work, not because it's some huge mystery. Maybe check the actual test points before blaming the meter, a bad crimp or a dirty contact does the same thing.