The **M5TS-52-R** is a specific infrared (IR) thermopile sensor module typically used for non-contact temperature measurement. It is part of a series often integrated into medical devices (like ear or forehead thermometers) and industrial automation tools. --- ### 1. Key Technical Specifications The following table summarizes the primary electronic characteristics of the M5TS-52-R sensor: | Parameter | Typical Value | Description | | :--- | :--- | :--- | | **Element Size** | 1.2 x 1.2 mm² | The active sensitive area of the thermopile. | | **Thermistor Resistance** | 100 kΩ | Used for ambient temperature compensation (at 25°C). | | **Output Voltage** | ~3.0 - 5.0 mV | Low-level analog signal (at Black Body 500K). | | **Field of View (FOV)** | ~90° - 100° | The angular extent of the observable world. | | **Operating Temp** | -20°C to +100°C | The range in which the sensor functions reliably. | --- ### 2. Internal Electronic Components The "M5TS" package is more than just a single component; it is a micro-system consisting of two main parts: 1. **Thermopile Chip:** This is a series of thermocouples connected in series. When IR radiation hits the chip, it creates a tiny voltage (the Seebeck effect) proportional to the temperature difference between the sensor and the object. 2. **Thermistor (NTC):** Because the thermopile measures a *differential* temperature, the module includes a High-precision Negative Temperature Coefficient (NTC) thermistor. This measures the "cold junction" or ambient temperature to allow the processor to calculate the absolute temperature of the target. 3. **Infrared Filter:** A silicon-based window that filters out visible light and only allows specific IR wavelengths (usually 5.5μm to 14μm) to pass through to the sensor. --- ### 3. Application Circuitry Because the output signal is in the **millivolt (mV) range**, the M5TS-52-R cannot be connected directly to a standard microcontroller GPIO. It requires: * **Operational Amplifier (Op-Amp):** A high-gain, low-noise chopper amplifier to boost the signal. * **ADC (Analog-to-Digital Converter):** Ideally a 16-bit or 24-bit ADC for high resolution. * **Voltage Reference:** A stable reference to ensure the NTC thermistor readings are accurate. --- ### 4. Pin Configuration (General) Most sensors in this series use a TO-5 or similar metal can package with four pins: | Pin Number | Function | Connection Note | | :--- | :--- | :--- | | **1** | Thermopile (+) | Positive analog output signal. | | **2** | Thermistor | One side of the NTC resistor. | | **3** | Thermopile (-) | Negative analog output signal (usually GND). | | **4** | GND / Case | Common ground and electromagnetic shielding. |