NTC Thermistor advice needed

Hi, I am a technician who frequently has to replace NTC sensors on the thermoblock boilers of coffee machines that get as hot as 300 degrees F. Quite a frequent repair! Instead of getting these sensors in Germany used, I want to order them direct from Digikey and there are several mfg like VISHAY and AMETHERM who put out the lug sensor I need. Ok, they are 10K ohm sensors but there is a variety of course specified by parameters I do not understand. Can somebody give me a recommendation here? Main thing is they need to withstand the temperature mentioned and be responsive as possible to changes in temperature. OR can I take my existing NTC sensor and have somebody extrapolate these params? Best way to go here!

Hi Mattinla,

Thank you for your inquiry. Please verify if these options (click here) will work for you:

Ok these are EXCELLENT, can you help me further.

I am currently getting these from GERMANY to use on JURA coffee machines that I repair.

They are now very expensive to get even USED, and take forever due to the Covid slowdown

The STEAM BOILER on these has a lug through hole, thermal sensor that frequently fails. It can get as hot as 320F, which seems to be slightly above the upper limit of 150C for most of these lug type sensors which is probably why it fails. There is no digital readout for temperature on these.

They are all 10K sensors. Can you recommend a specific MOLEX lug sensor with female connector that should do the job?

And a VISHAY one with no connector like 6” long….

I have used good sensors, is there any simple test I can do on these to do a match-up?

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Hi Mattinla,
Please verify specifications of 900-2138601635-ND | BC2896-ND, click here. The best way to test these is measure the resistance value at a certain temperature.

I can do that, can measure resistance at 100C. What do I do with that information, how do I match it up with yours?

Or is that just a testing methodology?

These also fail in very unpredictable ways!

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Selecting a thermistor with a similar beta value to the original would be important. This page offers an explanation of beta values and a calculator you can use to estimate the value for a given device based on resistance measurements at two known temperatures.