The thermocouple provides inaccurate temperature readings; the details are as follows
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The temperature controller and the accompanying thermocouple purchased online, after being connected, showed that the water temperature as measured by a thermometer was close to 60 degrees, while the instrument still indicated around 40 degrees. At room temperature, there is also a 2-3 degree error with the thermometer. How can this be resolved?
Use a thermistor for this purpose; it provides more accurate readings at low temperatures.
The cold-end compensation parameter should be set; it is recommended to use PT100 instead
The appropriate temperature sensor and model should be selected based on the operating environment; you can check the manual for this information
When selecting problem components, the part of the measuring rod that is exposed outside the device is affected by ambient temperature, which is one of the causes of such problems.
Thermal resistors are recommended; if thermocouples must be used, care must be taken regarding cold-junction compensation.
Firstly, thermocouples have a relatively wide temperature measurement range; measuring temperatures within a range of several dozen degrees is not a problem. Assuming the upper limit for a thermocouple’s temperature is 1000 degrees and the measurement accuracy is 1.0, a maximum deviation of 10 degrees is still within the limits of acceptable accuracy； Secondly, is there cold-end temperature compensation? A difference of 20 degrees is roughly equivalent to a difference in ambient temperature ； Furthermore, is the terminal pressed tightly? Is the thermocouple connector in good contact? Errors can also occur if there are problems with the wiring.
For temperatures below 500 degrees Celsius, it is recommended to use thermal resistors; for higher temperatures, thermocouples should be used!