Thermometer for JOBO processor

Recently I acquired a JOBO CPA 2 from another member in this FORUM. Shipping was a killer, but the seller did a great job in packing the processor and it arrived in perfect condition. It was complete except for its thermometer. I easily adapted a glass Kodak Color thermometer to fit into the unit's thermometer holder. It worked fine except twice I came close to accidentally hitting the glass thermometer and breaking it. Looked into acquiring a precision digital thermometer (brand, I forgot it, was mentioned by a FORUM member in another thread), but it was going for well over $100.00. I was on Amazon and came across a "Digital Refrigerator Thermometer LCD Display Thermostat" with battery and sending unit for all of $8.54. "Resolution is 0.1 degrees Fahrenheit". Accuracy was not stated, but other similar thermometers list 4 degrees (plus or minus 2 degrees?). The thermometer arrived in a small box with no paperwork. So I tested it several times over the past week, comparing it to my two Kodak Type 3 Process Thermometers at 68 degrees. I was floored... I can read the temperature readings on my Kodak Type 3 Process Thermometers to within maybe a quarter of a degree. That digital thermometer reads within a tenth of a degree. The two Kodak Process thermometers and the $8.54 digital thermometer gave me consistently the same readings within a quarter of a degree.

That's a nice little digital thermometer setup. It's a very good idea to not use the Kodak Color thermometer (except for occasional calibration etc)- it breaks easily and most of them contain a lot of mercury and cleanup will be a nightmare. Don't ask me how I know...

Found it on Amazon. I'd say you got lucky. One reviewer praised it for being within 1.5 degrees of his calibrated thermometer, another said it was TWENTY DEGREES off his. Of course once you compare it and know what this one reads when your solution or water bath is the right temperature as verified by your calibrated thermometer (I have a Kodak too, don't use it except to calibrate my others for reasons above) it's still useful. I'd say you got the real lucky bargain!

Bought another "Digital Refrigerator Thermometer LCD Display Thermostat" with battery and sending unit for under $9.00 from Amazon.
https://www.amazon.com/dp/B073RP1476...roduct_details
Maybe I'm just very lucky, but the second one was also within maybe a quarter of a degree of my Kodak Type 3 Process Thermometers at 68 degrees. It will be replacing my 40+ year old Beseler SS (with a lot of patina) dial thermometer.

Hmmm. ... I don't have any Jobo rotary processors per se, but a Jobo tempering box by itself. These reach equilibrium fairly quickly if the water you put in isn't too far off to begin with. From time to time I check the accuracy of mine, and today the water temp on the control dial was once again spot on with my Kodak Process thermometer. But I empty these every day, so that no grime or algae can build up on either the sensor or heating element.

I've generally found electronic thermometers too slow for my style, but in a pre-tempering situation like in a Jobo water jacket, they have plenty of time to equalize.

I bought some digital aquarium thermometers off Ebay for under 3 bucks, the sensor, which I suspect is a thermocouple?? is encased in hard plastic, very slow to respond but gives similar results as the Process thermometer given time.
These things, verified should work great with something like a Jobo, ie no quick change in temp.