1、 Overview:
This product is capable of receiving signal input from PT100 thermal resistor, with adjustable range, and can linearize PT100 to output a current signal of 4-20mA corresponding to temperature. The transmitter design is compact, with a low-power circuit design and all components using low-temperature drift, reducing the heating of the circuit and the impact of environmental temperature on the transmitter. Enhanced anti-interference design enables it to work stably in industrial grade environments of -40~80 ℃ for a long time.
2、 Features:
1. The two wire system operates in a 4-20mA mode, with better anti-interference ability and lossless remote transmission of signals.
2. Customize ASSIC circuits for higher integration and reliability
3. Software calibration, no movable potentiometer, lower temperature drift to<20ppm.
4. EMC anti-interference design, hardware watchdog, suitable for various industrial environments with harsh electromagnetic environments.
5. Pure digital PT100 calibration calculation, with higher accuracy.
3、 Main parameters:
·Power supply voltage: 12-36VDC, recommended 24VDC.
·Measurement range: -200 ℃~850 ℃, with a minimum transmission range of 50 ℃.
·Output signal: Two wire system 4-20mA, with a current resolution of approximately 1.6uA.
·Limit current: approximately 22Ma
·Temperature drift coefficient:<20ppm/℃ or 0.004% FS/1 ℃ (basic range)
·Working environment: temperature -40 ℃~85 ℃, humidity<85%, dry and non corrosive environment.
·Measurement accuracy: 0.1% FS (calibrated basic range).
4、 Outline dimensions and wiring diagram:

Wiring diagram description:

5、 Key calibration
Adjustment of zero and full scale of temperature transmitter (for LCD meter head adjustment)
Open the LCD meter cover, (WZ) is the zero adjustment potentiometer, and (WS) is the full adjustment potentiometer.
Adjustment method: First remove the pt100 thermistor, and then use a standard resistance box. At 100 Ω, adjust the "Z" potentiometer to display 00.0. At 138.5 Ω, adjust "S" to display 100.0, and repeat the fine adjustments several times to meet the standard requirements.
Note: The transmitter has been debugged before leaving the factory, and users do not need to perform further debugging. If debugging is required, please call the manufacturer for technical guidance.
6、 Precautions
1. This transmitter is designed with a 2088 explosion-proof aluminum casing, so it is defined as installed inside the 2088 explosion-proof aluminum casing. The customer's different structural designs require them to solve installation problems themselves.
2. Calibration of the transmitter is achieved by using a standard resistance box, adjusting the resistance box to ensure that the resistance value of the resistance box matches the calibrated resistance value.
3. The transmitter adopts a single line calibration connection, so it is best to use an analog transformer power supply for the transmitter's power supply. The switch power supply has the characteristics of high leakage current and ripple, which can cause leakage current between the transmitter and the instructor computer, affecting calibration accuracy.
4. If the device requires a relatively small transmission range, such as 0-50 degrees, and high-precision acquisition and transmission are required, it can be calibrated separately to 0-50 degrees. Select the appropriate amplification factor according to the signal and calibrate it separately.
5. Due to the limitations of panel input data, some data such as the zero position and full scale of the calibration resistor can be input as decimals during communication calibration, such as 100.01. However, in panel state, only 100 can be input. Moreover, once a value with a decimal point is calibrated in communication state, it will be automatically rounded in panel state, and the transmitter will not recognize these changes. Therefore, users of the operation must pay attention to these matters.