I. Differences Between Thermal Resistance and Thermocouple

1.Thermistors and thermocouples are like two detectives with different personalities in temperature measurement:

2.Thermistor: Measures temperature through resistance changes, commonly using PT100. Wiring needs to consider a three-wire system to eliminate lead errors.

3.Thermocouple: Utilizes the thermoelectric effect. Attention must be paid to the positive and negative poles during wiring, and compensating leads cannot be replaced.

Essential difference: Thermistors are more accurate in measuring low temperatures, while thermocouples are suitable for high-temperature environments.

II. Three-Step Wiring Process for Thermal Resistance

1.Wire Color Identification: Red is the common terminal, and white/blue are signal wires (variances may exist across different brands).

2.Three-Wire Connection: Connect the two wires of the same color to adjacent terminals, and the third wire to the opposite terminal.

3.Shielding Handling: Ground the metal mesh shield at one end to avoid signal interference.

III. Wiring Precautions for Thermocouples

1.Polarity Must Not Be Reversed: Red wire is the positive pole (taking K-type as an example). Reversed connection will cause abnormal temperature display.
2.Compensating Conductors: Ordinary copper wires will lead to measurement errors; dedicated compensating conductors must be used.
3.Cold Junction Compensation: The internal circuit of the temperature controller will automatically compensate for changes in ambient temperature.
4.Insulation Treatment: Avoid multi-point grounding to prevent loop interference.