Shoutout to the guy who showed me how to test sensors with a magnet on a job site in Phoenix

I was out in Phoenix last month on a new build and this old timer walked me through using a simple magnet to check door sensors instead of my meter. Saved me like 20 minutes of crawling around and made me look like I knew what I was doing. Has anyone else picked up a weird trick like that from a random person on site?

2 comments

2 Comments

caleb_thomas935d ago

Man that Phoenix heat is brutal, I remember working a warehouse job out in Surprise once where the sun felt like it was cooking the tools in your hand. That magnet trick is a lifesaver though, I had a similar thing happen to me with a sparky who showed me you can use a car key to tap a thermostat wire and see if it's live. Saved me a trip back to the truck for my tester. And yeah you're right about the reed switch thing, the guy who showed me made sure to point out it only works on the old school mechanical ones, not the digital hall effect ones. But honestly most of the sites I've been on still use the cheap reed sensors so it's been useful way more often than not.

felix1476d ago

That "saved me 20 minutes" part is what got me. Were you using a standard multimeter before or something more specific like a voltmeter with those long probe leads? I ask because I've seen guys spend way too long trying to get a good reading on those recessed magnetic contacts, especially when they're mounted up in a door frame with that foil tape. The magnet trick only works if the sensor is actually a reed switch though, right? If it's one of those newer hall effect sensors, a magnet would either do nothing or give you a false reading. Just wondering if he warned you about that difference or if it was just "stick the magnet to it and see what happens.