Characteristic line for Pt 100 resistor of tolerance-classes

The lower bound of temperature for the limit deviation its about the available verify requirement limited of –196 °C (-195,80°C are the boiling point from the nitrogen, a usual temperature for calibrate). The upper limit of temperature are fixed of +661 °C , (660,323 °C are solidification point from aluminium, a usual temperature for calibrate). The reasons are, that the analysis found on industry resistors a lot of significant deviants of temperature over 650 °C. That’s why in these temperature range the limit deviation for the thermometer or resistors between the producer and user should be specified.

The values of limit deviation for resistance thermometers are in the following table:

After DIN EN 60751 amounts to 100,000 ohm the face value with 0 ºC. You can speak therefore also from a Pt 100-temperature-sensor. In addition, also temperature-sensors become with face values of 200; 500 and 1000 ohm offered. Their advantage lies in the higher sensitivity, that means a bigger alteration of the resistance-values in dependence on the temperature. The resistance-alterations in the temperature-area until 100 ºC are:

• 0,4 Ohm/ K bei Pt 100
• 0,8 Ohm/ K bei Pt 200
• 2,0 Ohm/ K bei Pt 500
• 4,0 Ohm/ K bei Pt 1000

As further feature size defines DIN a middle temperature coefficient α between 0 ºC and 100 ºC. He gives the middle of resistance amendment, covered on the face value with 0ºC at:

R₀ and R₁₀₀ are the resistance-values with the temperatures 0 °C and 100 ° C .