What other methods are there for thermocouple cold-end temperature compensation?

In addition to the calculation correction method using the intermediate temperature law and the cold end constant temperature method, there are several common thermocouple cold end temperature compensation methods:
Compensation wire method
Principle: The compensation wire has the same thermoelectric characteristics as the connected thermocouple within a certain temperature range. Extend the cold end of the thermocouple to a place far away from the heat source and with a relatively stable temperature, so that the cold end temperature is fixed, thereby reducing the impact of cold end temperature changes on the measurement.
Application: Select a matching compensation wire according to the type of thermocouple, connect one end of it to the cold end of the thermocouple, and connect the other end to the measuring instrument or cold end compensation device.
Electronic compensation method
Principle: Use electronic circuits to automatically measure the cold end temperature, and generate corresponding compensation voltages according to temperature changes. The compensation voltage is added to the thermoelectric potential of the thermocouple to achieve automatic compensation of the cold end temperature.
Application: Electronic compensation chips or circuit modules are usually integrated in the thermocouple measurement circuit. These modules can monitor the cold end temperature in real time and perform corresponding compensation calculations and voltage adjustments. Some intelligent temperature measuring instruments have built-in electronic compensation functions, which can directly perform cold end temperature compensation on thermocouple signals and display accurate measurement temperatures.
Bridge compensation method
Principle: Use the voltage generated by the unbalanced bridge to compensate for the change in thermoelectric potential caused by the change in the cold end temperature of the thermocouple. One arm of the bridge is composed of temperature-sensitive components such as thermistors, whose resistance changes with the cold end temperature, thereby changing the output voltage of the bridge to offset the effect of the cold end temperature change on the thermoelectric potential of the thermocouple.
Application: Combine the bridge with the thermocouple measurement circuit, and adjust the parameters of the bridge so that it can generate a suitable compensation voltage at different cold end temperatures. In some industrial temperature measurement systems, this method is often used to perform centralized cold end temperature compensation on multiple thermocouples.