Baker Instruments MM2P Max-Min Thermometer, Beige

Cheaply made. Would not function right out of the box.

Good product.

I purchased two of these Baker recording thermometers. One didn't work at all and was quickly replaced by Amazon. The remaining two work but are awkward to use. The Fahrenheit scale is located in the center of the instrument and the numbers are largely blocked out by the re-set button, leaving commonly used temperatures reading zero. The Celsius scale is located on the outside and readable, but probably not widely used in the U.S. This thermometer works but is very awkward and will leave you frustrated and confused every time you use it. There are a lot better recording thermometers on the market for just a little more money - skip this one.

Am I missing something about how this is supposed to work? The indicator bars are supposed to remain inside the red liquid in the column. If the red liquid moves up, retracting past either bar, it (the surface tension at the red-clear interface) is supposed to drag the bar with it, overcoming the magnet that is holding the bars in place (actually by static and kinetic/moving friction, the magnet just supplies the normal force). Yes? To reset, you hold in the button that displaces the magnet back away from the bars, allowing both indicator bars to settle (by gravity) down to the current red-clear interface on each side. I think I understand how this is supposed to work using the forces of surface tension, magnets and gravity.However, in mine, the magnet is too strong, and the maximum indicator bar is firmly held in place, and the surface tension at the red-clear interface is too weak to drag the bar as temperature increases, perhaps because the magnet is too strong/close. Or the bar is undersized or the glass tube is oversized. See the first picture of the thermometer when cold (near freezing). See the second picture(room temp) of the indicator bar stuck inside the clear liquid on the max side, rather than having been drug upwards by the red-clear interface. It did manage to move up nearly 20F from it's starting position before it got stuck and broke the surface tension. I'll have to throw it back in the freezer to get the red liquid back down so I can reset it.On the minimum side the bar does seem to move with cooling temps, but it will stick for a bit, then quickly jump by 5~10F and overshoot the red-clear interface, so that the apparent minimum temperature reached will be 5-10F less than actual. This indicates that the coefficient of static friction is significantly greater than that of kinetic friction ... the glass or bars are too rough and need to be polished.So, do I understand the intricate balance of forces of how a min-max thermometer like this is supposed to work? If so, this crude implementation doesn't work because it hasn't balanced those forces reliably. I only paid $8 and shouldn't be surprised that it doesn't work. Maybe I can put some shims in front of the magnet to move it farther away from the bars to reduce the normal force so that there is less static/kinetic friction and the surface tension can overcome it.Or, am I missing something?I am giving this 2 stars rather than 1, not because it works well (it doesn't), but because it provided me with an hour of intellectual entertainment.

Neither one I ordered worked... both had air bubbles in them. Ended up throwing both in trash and bought different brand.