# Replacement sensor for stc 1000



## 431neb

Can anyone point me in the right direction on ebay (or similar) for a replacement sensor for an STC 1000?

I have a new controller and I've lost the damn lead / probe.

There seem to be so many different ones available online but none look like the ones that are usually supplied.

Thanks in advance.


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## Spoonta

Pm you address I have a spare one you can have


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## QldKev

Looks like you've scored one, so all good.

For anyone reading this later and is chasing one, on ebay search for a thermistor "NTC 10K ohm". Most will be just the thermistor without a cord, but some will be a complete cord. It may have a slightly different end on it, but as long as its NTC and 10K ohm, with a beta value of 3435 all is good.


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## 431neb

spoonta, thanks very generous!

Qld Kev thanks also.

Like this one ?

http://m.ebay.com.au/itm/261435654549?nav=SEARCH

Sorry I'm on my phone so my post is brief.

Thanks boys.


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## QldKev

Yep, that would work great.


This one has a screw in fitting.
http://www.ebay.com.au/itm/New-2M-NTC-10k-Thermistor-Temperature-Sensor-Probe-Cable-for-TEMP-Controller-/141128161186?pt=AU_B_I_Electrical_Test_Equipment&hash=item20dbe4d7a2
or a 5m version
http://www.ebay.com.au/itm/New-5M-NTC-10k-Thermistor-Temperature-Sensor-Probe-Cable-for-TEMP-Controller-/131059198622?pt=AU_B_I_Electrical_Test_Equipment&hash=item1e83bcaa9e


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## Beer Ninja

A 2 metre version and a 5 metre version available. $5.48 and $3.98 including delivery.

http://www.ebay.com/itm/400612392441

http://www.ebay.com/itm/380777414829


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## professional_drunk

If your not after the stock standard probe, you can buy them from keg king. These also fit thermowells.


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## verysupple

QldKev said:


> Looks like you've scored one, so all good.
> 
> For anyone reading this later and is chasing one, on ebay search for a thermistor "NTC 10K ohm". Most will be just the thermistor without a cord, but some will be a complete cord. It may have a slightly different end on it, but as long as its NTC and 10K ohm all is good.


Yup, the STC-1000 does indeed use a NTC (negative temperature coefficient, i.e. higher temp = lower resistance) 10k ohm (at 25 C) thermistor. However, thermistors work by being a temperature dependent resistor. The controller then uses that variable resistor with a reference resistor in a voltage divider circuit to work out the temperature. The problem is that not all NTC 10k thermistors have the same temperature dependence. i.e. at different temperatures they have different resistances (or in technobabble, they have different Steinhart-Hart coefficients (or beta parameters)).

Anyhoos, long story short, for those reading this in the future who want to buy a new probe online, you need one with a beta value of 3435 or the STC-1000 will tell you the wrong temperature. And no, you can't just change the offset because the difference is non-linear.

EDIT: I read in a thread on some other homebrewing forum h34r: that the STC-1000 uses a NTC 10k with a beta value of 1470. This turned out to not be correct.


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## 431neb

Thanks all. Yes verysupple, I had to read your post three times but it seems that 10 k thermistors are listed on ebay with a beta of 3435 which is what I bought. Thanks for your informative post. When it arrived I will test and (hopefully remember to) add a confirmation of it's success or failure so that that this thread can be 100% in it's confirmation of the above.


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## mr_wibble

It's a bit pricey as simply a loss replacement, but I use a Mashmaster stainless probe wired into my STC1000 as a drop-in replacement.
It works really well.

http://mashmaster.com.au/p/366867/ntc-sensor-stainless-steel-probe-optional-extra-for-fridgemate-brewmate.html


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## Ducatiboy stu

Make sure you re-calibrate when using a new probe


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## Pogierob

verysupple said:


> Anyhoos, long story short, for those reading this in the future who want to buy a new probe online, you need one with a beta value of 3435 or the STC-1000 will tell you the wrong temperature. And no, you can't just change the offset because the difference is non-linear.
> 
> EDIT: I read in a thread on some other homebrewing forum h34r: that the STC-1000 uses a NTC 10k with a beta value of 1470. This turned out to not be correct.


Just did a mad dash over to eBay to check my purchase. 

Lucky I got the right one. 

Great info, cheers!!


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