Temperature sensor works

Because the temperature of the cold sensor of the temperature sensor sensor often changes, and the temperature sensor requires the temperature of the cold end to remain unchanged, the magnitude of the thermoelectric voltage (voltage) can be proportional to the measured temperature, if the ambient temperature of the cold end changes. , will seriously affect the accuracy of the measurement. Therefore, the secondary instrument should automatically compensate for this error of the temperature sensor.
For example, the temperature of the cold end is 20 degrees, and the temperature measured at the corresponding measuring end is 100 degrees, but due to the change of the cold end temperature (because the temperature environment is generally not possible to be constant temperature), the temperature difference is changed from 20 degrees to 18 degrees. Larger, then the corresponding measurement of the temperature will be a corresponding change of 102, affecting the accuracy of the measured value. In order to ensure that the measured value does not change, the secondary instrument should automatically compensate the cold end by 2 degrees, maintain it at the original 20 degrees, and keep the measured value at 100 degrees, so as to ensure the accuracy and stability of the measured value.
If the temperature environment to be measured at the hot end is far away from the secondary instrument, then the connection line between the temperature sensor temperature sensor and the secondary instrument must use the temperature sensor special compensation wire. The compensation wire is matched with the matched temperature sensor. A nominal pair of thermoelectric potentials (voltages) (direct stated national standard values) with the same pair of conductors with insulating layers, connecting them to temperature sensors and measuring devices. Compensation wire is divided into extended and compensated types.
It should be noted that: When using the temperature sensor to compensate for the wire, attention must be paid to the model matching. The polarity cannot be connected wrongly. The positive electrode of the temperature sensor is connected to the red wire of the compensation wire, and the negative electrode is connected to the remaining color. The temperature of the connecting wire of the compensation wire and the temperature sensor must not exceed 100°C. The compensating wire of the temperature sensor can only function as an extended thermal electrode, so that the cold end of the hot electrode moves to the meter terminal. Does not compensate for the cold end. The compensating conductors compensate for the error caused by the temperature change at the connection to the temperature sensor.