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Why could I get wrong temperature measurements from a “NI1000 sensor” when connected to my TM3TI4 module ?

It exists two main categories of NI1000 standard (and few people in industry world is aware of that situation ) and the TM3TI4 module is designed to be compatible only with one of the 2 standards
There are similar standard because both providing same resistor value 1000 ohm at 0°C , also nearly linear from -60°C to 200°C , but with a different coefficient  Alpha  in the formula  Resistance= f(Alpha, Temperature) ,  giving the variation of the provided/read resistance value, depending on the temperature . Alpha can be else 5.000 else 6.180 depending on the referred standard .

TM3TI4 is compatible with NI1000 temperature sensors, with coefficient of 6180 ppm/K.   There are named NI1000-6180 or NI1000 DIN43760 or NI1000 Sauter or generally NI1000 .

TM3TI4 is not compatible  with NI1000  temperature sensor with coefficient of 5000 ppm/K.  There are named Ni1000 TK5000, Ni1000 L&G, Ni1000 Landys, or Ni1000 Siemens,  or generally LG-NI1000, there are mainly used in HVAC systems.
Using the wrong NI1000 would lead to a temperature error measurement as (to figure out the error):
0 at 0°C
less than 4°C at 20°C
11°C at 60°C  ( measured 49°C instead of 60°C°)
17°C at 100°C ( measured 63°C instead of 100°C)
As no information regarding this limitation or compatibility is present into our TM3 documentation. and due to the fact there is nothing to adjust into the TM3TI4 configuration (except selecting unit °C or °F), nobody could think connecting any NI1000 sensor could involve wrong measurements .
Then, before to order it or to connect it to the TM3TI4 module, it’s strongly recommended to have a look into the datasheet of the NI1000’s provider we plan to use, to find any information in order to make clear if such NI1000 would be compatible with the TM3TI4 or not.
If it’s absolutely not written any reference to the ‘magic coefficient’ 6180 or 5000, we can check if the curve or conversion table describing the sensor includes these 2 points (for any NI1000-6180 standard these points belong to the curve/ conversion table) :  (120°C, 1760 ohm),  (200°C, 2406 ohm)
If yes, then such sensor would suit to be used with TM3TI4 module

The two attached documents are providing the conversion tables temperature=f(resistor) for these 2 NI1000 standards
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