Temp sensor problem

I have used this sensor since late 2015 without any problems in 30+ brews http://www.auberins.com/index.php?main_page=product_info&cPath=20_15&products_id=189 . I also bought the braided cable with RTD connector.

However on my last brew the temp shown on my Auber PID was 10 degrees more than the actual temp of the liquid. I used a kettle thermometer and also a handheld thermometer (Lavatools Javelin which is similar to a Thermapen) to double check the liquid temp. In the past I have seen maybe a 1 degree difference but never one this big.

Has anyone else experienced something similar and found a solution short of replacing the sensor?

Check the resistance of the red pair - it should be a few ohms at most, then check first one red to white/blue resistance and the then the other red to white/blue resistance. Both should be the same, and equal to the table value of a PT100 resistor at that temperature plus the resistance around the red pair of wires.

If both red to white/blue readings are the same, but things don't add up, then there is extra resistance in the white wire. If there is extra resistance in one of the red to white circuits, there is extra resistance in the red wire used for the higher resistance.

Then check and clean the connections throughout the circuit. A few ohms of extra resistance on either the red pair or the red/white pair of the wires will throw the readings off.

If the resistance is lower than expected, then there's a short somewhere, and you should measure the cable separately from the sensor, and measure the sensor directly to work out which is wrong. You can just replace the cable with three identical wires.

its fairly common for the wiring to develop a short in the wiring or at the connectors themselves where they are soldered.. this goes for any of these sensors ive seen but is especially common in the cheaper stainless braided cable versions that auberins ironically sells as an upgrade. The wires inside are tiny compared to the standard cable and the stainless braid kinks very easily.


Coincidently I was just commenting about how these sensors are the same ones as available on ebay for $12 here so you can replace it fairly cheaply if you want... (even though the built in connector is 4 pin its still only using 3 or the pins.
http://www.ebay.com/itm/RTD-Pt100-T...560657&hash=item1eb2a071b4:g:lL0AAOSwqBJXXWGy

of course you can always message Auberins and see if they will replace it for you too...

I use these now myself for a few years and recommend them over the stainless braided stuff...
http://www.ebay.com/itm/RTD-PT100-T...946264?hash=item280fedfa98:g:1SAAAOSw-zxWm6lk

Thank you both for your helpful comments. I will test the current sensor as suggested by dyqik and if I can't fix it I'll follow one of augiedoggy's ebay links and buy a replacement.

My PID is now displaying the EEEEEE error code for the temp sensor so I ordered the $20 replacement that audiedoggy recommended from ebay.

I have also been exchanging troubleshooting correspondence (quite a bit of it actually) with Auberins customer service. In their last email they asked me to test the cable resistance with a multimeter and get back to them with the results. I don't know if anything will come of it such as an offer to replace either the braided cable or the temp sensor but at least they are very responsive when emailed.