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Sensor transmitter matching using one of the above-named methods significantly improves
the temperature measurement accuracy of the entire system. This is due to the fact that to
calculate the temperature measured, the transmitter uses the specific data pertaining to the
connected sensor instead of using the standardized curve data of a sensor.
Non-repeatability
As per EN 61298-2
Physical input measuring range of sensors
Non-repeatability
10 to 400 Ω
Pt100
15 mΩ
10 to 2000 Ω
Pt200, Pt500, Pt1000
100 ppm x measured value
-20 to 100 mV
Thermocouples type: C, D, E, J, K, N
4 μV
-5 to 30 mV
Thermocouples type: B, R, S, T
3 μV
Long-term stability
≤ 0.1 °C/year (≤ 0.18 °F/year) in reference operating conditions
Influence of ambient temperature (temperature drift)
Impact on accuracy when ambient temperature changes by 1 K (1.8 °F):
Input 10 to 400 Ω
0.001% of the measured value, min. 1 mΩ
Input 10 to 2000 Ω
0.001% of the measured value, min. 10 mΩ
Input -20 to 100 mV
0.001% of the measured value, min. 0.2 μV
Input -5 to 30 mV
0.001% of the measured value, min. 0.2 μV
Typical sensitivity of resistance thermometers
Pt: 0.00385 * Rnom/K
Example Pt100: 0.00385 x 100 Ω/K = 0.385 Ω/K
Typical sensitivity of thermocouples
B: 10 μV/K
C: 20 μV/K
D: 20 μV/K
E: 75 μV/K
J: 55 μV/K
K: 40 μV/K
N: 35 μV/K
R: 12 μV/K
S: 12 μV/K
T: 50 μV/K
Examples of calculating the measured error with ambient temperature drift:
Example 1:
Input temperature drift ϑ = 10 K (18 °F), Pt100, measuring range 0 to 100 °C (32 to 212 °F)
Maximum process temperature: 100 °C (212 °F)
Measured resistance value: 138.5 Ω (DIN EN 60751) at maximum process temperature