Difference between thermistor and thermometer readings
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There is a discrepancy between the thermoresistors sent to the DCS and the temperature readings from the field instruments; the causes and solutions for this issue are discussed.
Thermistors reflect temperature changes through variations in their resistance; at long distances, the resistance of the wires cannot be ignored, which leads to values that are higher than the actual ones. On-site thermometers are more accurate
The instrument itself has errors; if that’s the case, I usually trust the one with higher precision. I will trust the thermistor. . . . (In a three-wire system,) if the error is constant, for example, it’s always 2 degrees off, then it can’t be eliminated, right? . .
Is the gap large? If it’s small, then we need to see whether it’s a significant gap. There are different reasons for each case, you know
There must be differences; there are certainly variations in the accuracy of the temperature counters on site and in the resistances. Also, how many wires does the resistor have, and what is the precision of the DCS components?