TMT31 Temperature Transmitter Overview
The TMT31 temperature transmitter is a high-performance, high-reliability industrial temperature transmitter widely used in process control fields such as petroleum, chemical, power, and metallurgy. It can convert resistance temperature detector (RTD) or thermocouple (TC) signals into standard 4-20mA analog signals or digital signal outputs, facilitating remote transmission and system integration.
This manual is intended to help users quickly master the installation, wiring, configuration, and maintenance methods of the TMT31, ensuring long-term stable operation of the instrument.
TMT31 Core Features and Advantages
- High-precision measurement: Supports various RTDs such as Pt100 and Pt1000, and B, E, J, K, N, R, S, T type thermocouples, with measurement accuracy up to ±0.1°C.
- Wide range: Suitable for industrial temperature measurement scenarios from -200~850°C (RTD) and -200~1800°C (TC).
- Flexible output: Standard 4-20mA+HART, optional PROFIBUS-PA, FOUNDATION Fieldbus and other fieldbus protocols.
- Rugged protection: Aluminum alloy or stainless steel housing, protection class IP66/IP67, suitable for harsh working conditions.
- Easy configuration: Supports PC software, handheld communicator, or local buttons for parameter setting and calibration.
TMT31 Technical Parameters Detailed Explanation
The following are the main technical parameters of the TMT31 temperature transmitter for selection and procurement reference.
| Parameter Item | Specification Description |
|---|---|
| Input Signal | RTD: Pt100, Pt1000; TC: B, E, J, K, N, R, S, T |
| Output Signal | 4-20mA + HART (two-wire) |
| Supply Voltage | 12~45V DC (intrinsically safe: 12~30V DC) |
| Accuracy | ±0.1°C (RTD), ±0.5°C (TC) |
| Ambient Temperature | -40~85°C |
| Protection Class | IP66/IP67 |
| Explosion-proof Certification | Ex ia IIC T6 Ga / Ex d IIC T6 Gb |
Installation and Wiring Guide
Installation Steps
- Confirm the installation location: avoid strong vibration, direct contact with corrosive media, and ambient temperature exceeding limits.
- Installation method: threaded installation, flange installation, or ferrule installation can be selected to ensure sufficient sensor insertion depth.
- Electrical connection: connect power supply, output signal, and sensor leads according to the wiring diagram, and note that the shielding layer should be grounded at one end.
- Power-on check: after power-on, observe whether the transmitter starts normally and whether the output current changes with temperature.
Wiring Precautions
- Use shielded cables, and ground the shielding layer on the control room side.
- Avoid parallel laying with power cables to prevent electromagnetic interference.
- Intrinsically safe transmitters must be used with safety barriers and comply with explosion-proof regulations.
Configuration and Commissioning Methods
The TMT31 supports multiple configuration methods, and users can choose according to site conditions.
- PC configuration: Connect to a computer via USB interface or HART modem, and use dedicated software to set range, unit, damping, etc.
- Handheld communicator configuration: Use a HART handheld communicator for on-site parameter modification.
- Local button configuration: Some models are equipped with LCD display and buttons for direct operation.
After commissioning, it is recommended to perform a loop calibration to ensure that the transmitter output is consistent with the host computer display.
Common Faults and Maintenance
| Fault Phenomenon | Possible Cause | Solution |
|---|---|---|
| Output current always 4mA | Sensor open circuit or wiring error | Check sensor and wiring |
| Output current always 20mA | Sensor short circuit or range setting error | Check sensor and range configuration |
| Large output fluctuation | Electromagnetic interference or poor grounding | Check shielding and grounding |
| No output | Power failure or transmitter damage | Check supply voltage, replace if necessary |
Regular maintenance can extend the service life of the transmitter. It is recommended to check wiring and sealing conditions every six months.
Selection and Ordering Information
The following information must be specified when selecting:
- Sensor type and graduation
- Measurement range
- Output signal and communication protocol
- Process connection method and material
- Explosion-proof requirements
- Housing type and protection class
For complete technical information, please download TMT31 Chinese Manual.pdf to obtain detailed dimension drawings, wiring diagrams, and certification information.