Delta: Temperature Measurement Module (DVP04TC-S)

The Thermocouple Temperature Sensor
The thermocouple is generated by Seebeck Effect. Generally speaking, a thermocouple is composed of conductors of two different materials. When a temperature difference occurs at the two ends of the thermocouple, the thermocouple will generate a voltage signal in proportional to the temperature difference. The voltage signal ranges from tens of uV to thousands of uV; therefore, we need to magnify the voltage when using it.

The thermocouple temperature sensor indicates temperature by differential voltage, and it has already eliminated external interferences when two pairs of data are performing differential operation. Therefore, it is much more stable than a thermistor, resistive thermometer or thermal resistor and is widely applied in the industry.

The thermocouple is a loop constructed by two different metallic wires welded or twisted together (see the figure below). Different metals make two junctions in the loop. One junction is called “measuring junction” or “hot junction”, and the other is “reference junction” or “cold junction”. Placing the two junctions in different temperatures will cause a loop voltage (i.e. Seebeck Effect), and the loop voltage is in proportional to the temperature difference between the two junctions.

DVP04TC is able to receive 4 points of external thermocouple temperature sensors (J-type, K-type, R-type, S-type, T-type) and convert them into 14-bit digital signals. The data in DVP04TC can be read/written by using FROM/TO instructions in the program of DVP-PLC MPU. There are 49 16-bit control registers (CR) in DVP04TC. The power unit and module of DVP04TC are separate, compact in size and easy to install. You can select temperatures in Celsius (resolution: 0.1°C) or Fahrenheit (resolution: 0.18°F).