Measurement Computing WEB-TEMP - Manual (Page 32)

WEB-TEMP User's Guide Specifications
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Note 7: Error shown does not include errors of the sensor itself. These specs are for one year while operation
of the WEB-TEMP unit is between 15 °C and 35 °C. Contact your sensor supplier for details on the
actual sensor error limitations.
RTD measurement accuracy
Table 6. RTD measurement accuracy specifications
RTD Sensor temperature
(°C) Accuracy error (°C)
maximum Accuracy error (°C)
typical Tempco (°C/°C)
PT100, DIN,
US or ITS-90
–200 2.913 2.784 0.001
–150 1.201 1.070 0.001
–100 0.482 0.349 0.001
0 0.261 0.124 0.001
100 0.269 0.127 0.001
300 0.287 0.136 0.001
600 0.318 0.150 0.001
Note 8: Error shown does not include errors of the sensor itself. The sensor linearization is performed using a
Callendar-Van Dusen linearization algorithm. These specs are for one year while operation of the
device is between 15 °C and 35 °C. The accuracy and tempco specifications include the accuracy of
the Callendar-Van Dusen linearization algorithm. The specification does not include lead resistance
errors for 2-wire RTD connections. Contact your sensor supplier for details on the actual sensor error
limitations.
Note 9: Resistance values greater than 660 Ω cannot be measured by the WEB-TEMP in the RTD mode. The
660 Ω resistance limit includes the total resistance across the current excitation (±Ix) pins, which is the
sum of the RTD resistance and the lead resistances.
Note 10: For accurate three wire compensation, the individual lead resistances connected to the ±Ix pins
must be of equal ohmic value. To ensure this, use connection leads of equal lengths.
Thermistor measurement accuracy
Table 7. Thermistor measurement accuracy specifications
Thermistor Sensor
temperature (°C) Accuracy error
maximum (°C) Accuracy error
typical (°C) Tempco (°C/°C)
2252 Ω –40 0.001 0.0007 0.001
0 0.021 0.008 0.001
50 0.263 0.130 0.001
120 3.473 1.750 0.001
5000 Ω –35 0.001 0.0006 0.001
0 0.009 0.004 0.001
50 0.115 0.049 0.001
120 1.535 0.658 0.001
10000 Ω –25 0.001 0.0005 0.001
0 0.005 0.002 0.001
50 0.060 0.028 0.001
120 0.771 0.328 0.001
30000 Ω –10 0.001 0.0005 0.001
0 0.002 0.001 0.001
50 0.019 0.009 0.001
120 0.267 0.128 0.001