View Full Version : JOBO ATL 1000 Temperature probe - any cheap alternative?

25-Sep-2017, 10:26
Hi, folks,

JOBO part #95444

I see similar water tank probes going for a couple of dollars (instead of $100.- they go officially for), and I was wondering if there is anybody here who tried to replace the probe in the machine with such alternative? I have zero knowladge of how these works though.

Thanks for your time, Vlad.

3-Oct-2017, 05:13

Same question here...


4-Oct-2017, 12:03
If you knew the specs of the temperature probe (voltage range etc) it probably wouldn't be hard to find a replacement. Without knowing the specs it would likely requiring some electronics reverse engineering to figure out what signals the probe is sending.

5-Oct-2017, 06:46
Many thanks for the answer, now, hopefully, there is someone who knows specifications of the probe?

I found a way to go around the faulty probe. You can follow my instructions:

My processor starts C41 developing process at a very low temperature (at around 32 C). You will need extra thermometer that you want to leave hanging in the first tank, with the top machine's lid open while running. Let the machine beep when it starts (it's just asking for the lid to be closed so it can proceed with processing). Now, keep your eyes on thermometer and wait until the developer solution reaches required temperature, then close the lid and let the prcess start.
It is possible that the water bath reaches 42 C or more while heating the solutions, but this slight overheating doesn't seem to cause any problems.

5-Oct-2017, 07:10
It will most likely be an NTC sensor since those are a lot more accurate than thermocouples (which are designed for big temp ranges). My money would be on a 10K NTC sensor since those are the most abundant, but if it has failed you won't be able to test the resistance.

I've got a working ATL1500 at home so if I get chance I'll see if I can figure out the resistance of the probe - it ought to be reasonably straight forward sitting it in a pot of hot water hooked up to a multimeter. It might be a while before I can get round to this.

6-Oct-2017, 03:29
Hi Ben, that would be great indeed, thank you! Love your portrait work!