Delta: Temperature Measurement Module (DVP04PT-S)

The Basic Concept of Platinum Temperature Sensor (PT100)

Platinum temperature sensor is highly accurate and stable and the quality of linearity between -200°C and 600°C is fairy good. Generally speaking, the temperature coefficient of PT100 temperature sensor is significant at low temperature -200°C ~ -100°C, and the quality of linearity is good at middle temperature 100°C ~ 300°C. The temperature coefficient becomes small the temperature is high, i.e. 300°C ~ 500°C. The resistance of PT100 is 100Ω when the temperature is at 0°C, which is the standard for a metallic temperature sensor. The use of PT100 temperature sensor should avoid the working current that is too big in order to reduce self-heating. It can therefore confine the rated current to be below 2mA. The self-heating of 1mW of PT100 will cause a temperature variation of 0.02°C ~ 0.75°C. Therefore, reducing the current of PT100 can also reduce the temperature variation. However, if the current is too small, PT100 will be interfered by noise easily. In the case, it is appropriate to confine the current between 0.5mA and 2mA.

DVP04PT temperature measurement module is able to receive 4 points of platinum temperature sensors (PT100 3-WIRE 100Ω 3850 PPM/°C (DIN 43760 JIS C1604-1989)) and convert them into 14-bit digital signals. The data in DVP04PT can be read/written by using FROM/TO instructions in the program of DVP-PLC MPU. There are 49 16-bit control registers in the module. The power unit is separate from the module and is compact in size and easy to install. You can select temperature displayed in Celsius (°C) or Fahrenheit (°F). Resolution of temperature in Celsius: 0.1°C and in Fahrenheit: 0.18°F.