The integrated temperature transmitter is used in conjunction with industrial thermocouples and thermal resistors. Two wire transmission mode (two wires are used as power supply input and signal output common transmission line). The industrial thermocouple and thermistor signal are converted into 4-20mA and 0-10mA output signals which are linear to the input signal or to the temperature signal. It can be directly installed in the junction box of thermocouple and thermal resistance to form an integrated structure. As a new generation of temperature measuring instruments, it can be widely applied in industrial sectors such as metallurgy, petroleum, chemical industry, electricity, light industry, textile, food, national defense and scientific research.    

Characteristics
It adopts silicone rubber or epoxy resin seal structure, so it is shock resistant, moisture resistant and suitable for installation in harsh field environment.
The field is installed in the junction box of thermocouple and thermoelectric resistance, and directly outputs the output signals of 4-20mA and 0-10mA. In this way, the cost of the expensive compensation conductor is saved, and the anti-interference ability of the signal in the long distance transmission process is enhanced.
The thermocouple transmitter has the function of automatic temperature compensation at the cold end.
High accuracy, low power consumption, wide range of temperature in use environment, stable and reliable operation.
A wide range of applications, it can be integrated with the thermocouple and thermal resistance to install the on-site installation structure, or it can be used as a function module installed in the detection equipment and the instrument panel.
The intelligent temperature transmitter can communicate with the host computer through the HART modem or carry out remote information management, configuration, variable monitoring, calibration and maintenance functions with the handset and PC.
The intelligent temperature transmitter can adjust the direction of the transmitter according to the actual needs of users, and show the medium temperature, the change of sensor value, the output current and percentage of the transmitter measured by the transmitter.

Work principle
A thermocouple or a thermistor sensor converts the measured temperature to an electrical signal and sends the signal to the input network of the transmitter, which contains zeroing and thermocouple compensation. The signal after zero adjustment is input to the operational amplifier to amplify the signal. The amplified signal is processed by V/I converter and output by 4 20mA DC current. The other way is processed by the A/D converter and displayed to the meter. There are two kinds of linearization circuits for transmitters, all of which adopt feedback mode. The thermal resistance sensor is corrected by positive feedback mode, and the thermocouple sensor is corrected by multi section broken line approximation. There are two ways to display the integrated digital display temperature transmitter.The temperature transmitter displayed by LCD is output by two wire mode, and the temperature transmitter displayed by LED is output by three wire system.  
Main technical parameters
1, input signal: thermocouple: K, E, J, B, S, T, N. Thermal resistance: Pt100, Cu50, Cu100 (three wire system, four wire system). The input signal of intelligent temperature transmitter can be set by hand and PC.
2, output signal: output 4 - 20mA DC signal in the range, linear with the thermocouple or thermal resistance input signal, or linearly with temperature. The intelligent temperature transmitter outputs 4 20 mA DC signals and superimposes HART standard protocol communication at the same time. The isolated temperature transmitter is isolated from input and output, Isolating voltage 500V, increasing the ability of resisting common mode interference, and is more suitable for networking with computers.
3, basic error: 0.5%FS, 0.2%FS, intelligent 0.2%FS;
4, wiring mode: two-wire system, three wire system, four wire system;
5, display mode: four bit LCD display site temperature, intelligent four bit LCD can be set through PC or handset to display any parameters of site temperature, sensor value, output current and percentage percentage.
6, working voltage: general model 12V-35V, intelligent 12V-45V, rated working voltage is 24V
7, allowing load resistance: 500 ohms (24VDC power supply); limit load resistance R (max) =50 (Vmin-12), for example, when rated operating voltage 24V, load resistance can be selected in 0-600 ohms.
8. Working environment: a: ambient temperature -25-+80 C (conventional type)
-25-+70 C (digital display)
-25-+75 C (intelligent)
B: relative humidity: 5%-95%
C: mechanical vibration f is less than 50Hz, amplitude is less than 0.15mm
D: no corrosive gas or similar environment;
9, the environmental impact coefficient: Delta is less than 0.05%/ degrees.