How to Use Pt100 Sensor with Transmitter?
The Pt100 temperature sensor is an instrument that converts a temperature variable into a transmittable, standardized output signal. Pt100 is a platinum thermal resistor, and its resistance will change with temperature. 100 after Pt means that its resistance value is 100 ohms at 0°C, and its resistance value is about 138.5 ohms at 100°C. Mainly used for the measurement and control of industrial process temperature parameters. Its working principle is that when the PT100 is at 0 degrees Celsius, its resistance value is 100 ohms, and its resistance value will increase approximately uniformly as the temperature rises. But the relationship between them is not a simple proportional relationship, but should be closer to a parabola.
However, this resistance is not a standard analog signal, so we need a transmitter to convert the resistance signal into a standard analog signal, and next we will introduce how to use it by choosing the model ATO-RTD-D2W of ATO good quality RTD sensor.
Open the protective case and you can see a 4-20mA transmitter installed.
Step 1: Wiring
- According to the wiring diagram, connecting the Pt100 sensor to the control instrument.
- Terminals 4 (yellow wire) and 5 (black) are connected to the sensor "+".
- Terminals 6 (white) are connected to the sensor.
- Connecting a humidity sensor to ports 3, 7, and 8.
- Connecting the power supply to ports 15 and 16.
After the power is turned on, the display meter automatically calibrates the sensor, the current Pt100 temperature is 20.4 ℃, and the CH2 shows the current humidity.
Using a sensor to measure a bucket of water that is being heated, and the temperature of the water is around 52°C.
Step 2: Testing
Connecting 24V to the output "+".
Connecting 0V to the "-" end of the detection instrument.
The SIG output signal is connected to the + end of the detection instrument.
The detection instrument detects the 9.86mA output signal.
Throw the sensor into hot water at 48°C, and the output of the transmitter is 11.93mA.
You can watch the video below if you want to see more details of how to use the Pt100 sensor with transmitter.
