The **M2TT-3A-R2/CE** is a high-precision, industrial-grade temperature transmitter, typically used for converting signals from temperature sensors (like RTDs or Thermocouples) into a standardized analog output. It is part of the M2 Series manufactured by **M-System** (now MG CO., LTD). --- ### 1. Key Technical Specifications The following table highlights the primary electronic characteristics of the unit: | Feature | Specification | |:---|:---| | **Model Type** | Mini-M Series Temperature Transmitter | | **Input Signal** | RTD (typically Pt100) | | **Output Signal** | 4 – 20 mA DC (Current Loop) | | **Power Supply** | 24V DC | | **Accuracy** | ±0.1% of span | | **Response Time** | ≤ 0.5 seconds (0 – 90%) | | **Isolation** | 3-way isolation (input to output to power) | | **Construction** | Plug-in style (socket base) | --- ### 2. Internal Electronic Components & Design The M2TT-3A-R2/CE utilizes several critical electronic stages to process signals: #### A. Input Conditioning Circuit * **Excitation Current:** For RTD inputs, the unit provides a constant current to the sensor to measure resistance changes. * **Burnout Protection:** It includes electronics to detect an open circuit in the sensor. If a wire breaks, the output is driven to a specific "upscale" or "downscale" safety limit. #### B. Isolation Stage * **Galvanic Isolation:** Uses optical or magnetic coupling to separate the input, output, and power supply. This prevents "ground loops" and protects delicate PLC/DCS equipment from high-voltage surges on the field side. #### C. Signal Conversion (Amplification) * **Linearization:** Since RTD resistance is not perfectly linear with temperature, the internal circuitry applies a linearization algorithm to ensure the 4-20mA output is proportional to the temperature, not just the resistance. * **Zero/Span Adjustments:** Accessible potentiometers on the front panel allow for fine-tuning of the electronic calibration. --- ### 3. Connection Diagram Overview | Terminal No. | Function | Description | |:---:|:---|:---| | **1 - 3** | Input | Sensor connections (A, B, B' for 3-wire RTD) | | **4 - 5** | Output | 4 – 20 mA DC signal to Controller/Recorder | | **7 - 8** | Power | 24V DC Power Input | --- ### 4. Certifications (CE Mark) The **"CE"** suffix in the model name indicates that the electronics comply with European Union standards for: * **Electromagnetic Compatibility (EMC):** The device does not emit excessive interference and is resistant to external electronic noise. * **Low Voltage Directive:** Ensures the internal power handling is safe for industrial environments.