Fridge Fun

[tractors1]

I use a remote temp monitor with a sensor in the freezer and another in the fridge. Got everything packed up and noticed the freezer at 18 degrees and the fridge at 65; thought being not very level was probably the problem and hoped things would improve once on the road. 3 hours later at our site freezer at 20 and fridge at 63, switched to electric and no improvement. Time for angst! Thought it very strange there was such a wide gap in the readings, so I swapped the sensors. Readings swapped also - now 60ish in the freezer, and 24 in the fridge. More nonsense. New batteries in sensors - no help. New batteries in monitor - no help. Monitor has a tiny hole to stick a pin into for a full reset. TADA! No idea why it whacked out; the setup has been working perfectly for over 10 years. Freezer at 1, fridge at 39 on electric now.


I still remember the professor who taught my Instrumentation course in college - the first sentence he uttered on day1 of class as he entered the room was "Never trust your instruments." I rarely have full 100% faith in them....

[padlin]

Good to know, hopefully I can remember it.

[dfandrews]

Similar thing happened at a campground recently: I was helping the camper across the road with why his battery wasn't getting charged while towing. We got some strange readings at his 7-pin receptacle and at various spots on the trailer. The VO meter had been sitting in the sun the whole time we were doing the debugging. Turned it off, put it in the shade for a while, then restarted our procedures. Ahah! Different, more viable numbers, and we solved the problem. Don't trust your instruments.
(Edit: BTW, it was a HF cheapie meter, that's basically good enough for continuity checks, and (now we know) questionable for viable numbers!)