When my son was “on the way” we went looking to buy a thermometer since we knew we’d need one. Being a geek, I looked on eBay and found a hospital/clinic grade WelchAllyn SureTemp. It was an older model, but seemed to be in good shape, and I got it for pretty cheap (like $30). It came with the Oral/Aux probe, but didn’t come with the wall holder, which is a slight issue, as I’ll find.
The unit, by and large, works great. It was pretty grimy when I got it, but it cleaned up with some IPA and cotton swabs. The problem was, since I was using it for my baby (then toddler) son, I wanted to use the under-arm mode. It defaults to the Oral mode, and you have to hold the mode button for 2 seconds to switch it. This can be changed if you read the Service Manual by placing the unit in the wall holder, and holding the mode button down while removing the probe. I don’t have the wall holder. Damn. A bit more reading in the Service Manual showed there is a magnetic read switch on the PCB that’s being toggled when placed in the wall holder. So, I grabbed a largish magnet (circular) ((the type you see a hook attached to. Think I got it at Harbor Freight)), and placed it on the front of the unit while holding Mode, and removing the probe. Viola! It went into Service, and I was able to change the default to ALY (Auxiliary) mode by default. Yay! Good luck (if you have one of these, and this behavior annoys you).
