Integrated temperature transmitter/sensor

The integrated temperature transmitter adopts a two-wire transmission method (two wires serve as a common transmission line for power input and signal output). It converts industrial thermocouple and thermistor signals into 4-20mA and 0-10mA output signals that are linear with the input signal or temperature signal. As a new generation of temperature measuring instruments, it can be widely used in industries such as metallurgy, petroleum, chemical, power, light industry, textile, etc.

Characteristics of integrated temperature transmitter/sensor

1. Adopting silicone rubber or epoxy resin sealing structure, it is shock resistant, moisture resistant, and suitable for installation and use in harsh on-site environments.
2. Installed on-site in junction boxes for thermocouples and thermal resistors, it directly outputs 4-20mA and 0-10mA output signals. This not only saves expensive
Compensating for wire costs and improving the anti-interference ability during long-distance signal transmission;
3. Thermocouple transmitters have automatic compensation function for cold junction temperature;
4. High precision, low power consumption, wide temperature range for use, stable and reliable operation;
5. Widely applicable, it can form an integrated on-site installation structure with thermocouples and thermistors, and can also be installed as a functional module in detection equipment
Used on the dashboard;
6. The intelligent temperature transmitter can communicate with the upper computer through a HART modem or with handheld devices and PCs to determine the model, scale, and range of the transmitter
Perform remote information management, configuration, variable monitoring, calibration, and maintenance functions;
7. The intelligent temperature transmitter can adjust the display direction of the transmitter according to the actual needs of the user, and display the temperature of the medium measured by the transmitter and the changes in sensor values
Conversion, output current, and percentage ratio;

Principle of integrated temperature transmitter/sensor

Thermocouples or thermal resistance sensors convert the measured temperature into electrical signals, which are then sent to the input network of the transmitter. This network includes relevant circuits such as zeroing and thermocouple compensation. The zero adjusted signal is input to an operational amplifier for signal amplification. The amplified signal is then processed by a V/I converter and output as a 4-20mA DC current; The other path is processed by an A/D converter and displayed in the header. There are two types of linearization circuits for transmitters, both of which use feedback methods. For thermistor sensors, calibrate using positive feedback method, and for thermocouple sensors, calibrate using multi segment line approximation method. There are two display modes. The temperature transmitter for LCD display outputs using a two-wire system, while the temperature transmitter for LED display outputs using a three wire system.

Integrated temperature transmitter parameters

1. Input signal: Thermocouples: K, E, J, B, S, T, N. Thermistor: Pt100, Cu50, Cu100 three wire system, four wire system. The input signal of the intelligent temperature transmitter can be set arbitrarily through a handheld device and a PC;
2. Output signal: Output a 4-20mA DC signal within the range of measurement, which is linear with the input signal of the thermocouple or thermistor or linear with temperature. The intelligent temperature transmitter outputs a 4-20mA DC signal and superimposes it with communication in accordance with the HART standard protocol; Isolated temperature transmitter: Input and output are isolated, with an isolation voltage of 500V, which increases the ability to resist 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 methods: two-wire system, three wire system, four wire system;
5. Display mode: Four digit LCD displays the on-site temperature, and the intelligent four digit LCD can be set through a PC or handheld device to display any of the parameters such as on-site temperature, sensor value, output current, and percentage;
6. Working voltage: Ordinary model 12V-35V, intelligent model 12V-45V, rated working voltage is 24V
7. Allowable load resistance: 500 Ω (24VZR power supply); The maximum load resistance R (max) is 50VMin-12. For example, at a rated operating voltage of 24V, the load resistance can be selected and used within the range of 0-600 Ω.
8. Working environment: a: ambient temperature -25-+80 ℃ (conventional type)
-25-+70 ℃ (digital display type)
-25+75 ℃ (intelligent type)
b: Relative humidity: 5% -95%
c: Mechanical vibration f ≤ 50Hz, amplitude ≤ 0.15mm
d: No corrosive gas or similar environment;
9. Environmental impact coefficient: δ ≤ 0.05%/℃.

Integrated temperature transmitter measurement range