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Check your bond meter before relying on it
Was troubleshooting a weird static discharge issue on a King Air last week. Spent 2 hours chasing a ground loop that didn't exist, swapping boxes and reterminating connectors. Turns out my bond meter was off by 0.1 ohm because the leads were getting flaky. Ran a quick self-test against a known good jumper and caught it. Anyone else ever waste a shift because their test gear lied to them?
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martin.felix22d ago
Phoenix is where I had a similar problem with a freon leak detector back in '09. Spent a whole afternoon pressurizing and re-pressurizing a 737 pack because the sniffer kept showing a leak at a brazed joint. @elizabethhayes is right about this, 0.1 ohms is a small number but the issue is the meter was trending wrong over the whole range, not just at that spot. I swapped the sniffer probe and the same joint showed clean, but by then I'd already swapped two expansion valves and a compressor for no reason. The real lesson for me was that meters drift differently than what we expect, especially after they get banged around in a tool bag for a few years. I check my bond meter against a 0.5 ohm shunt on the first of every month now.
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elizabethhayes22d ago
Honestly I'm not sure 0.1 ohms is worth two hours of headache. Those bond meters are finicky instruments and if you're relying on it to the hundredth of an ohm you're probably overthinking it. A good visual inspection and a quick tug on the connectors would have caught the same issue without needing to run a self-test. I've seen guys chase phantom decimal points when the real problem was just a dirty connection.
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