The **HTS-4B-R/Q** is a high-performance infrared (IR) sensor belonging to the Thermopile family, manufactured by **Heimann Sensor**. These sensors are specifically designed for non-contact temperature measurement and gas analysis. --- ### 1. Key Technical Specifications The "HTS" series represents a multichannel configuration (quad-channel), allowing for simultaneous monitoring of different IR wavelengths. | Parameter | Typical Value / Description | | :--- | :--- | | **Sensor Type** | Thermopile (Quad Channel) | | **Element Size** | ~1.2 x 1.2 mm² per channel | | **Filter Window** | Specialized IR Bandpass Filters | | **Package** | TO-39 (Metal Can) | | **Thermistor** | Integrated (for ambient temperature compensation) | | **Sensitivity** | ~20 to 50 V/W (depending on filter) | --- ### 2. Internal Electronic Components The HTS-4B-R/Q consists of four distinct sensing areas and internal compensation circuitry: 1. **Thermopile Chips:** These are micro-machined silicon membranes containing a series of thermocouples. They convert thermal energy (IR radiation) into a small DC voltage (microvolts to millivolts). 2. **Optical Filters (The "R/Q" designation):** * The sensor features four separate optical windows. * Usually, one channel acts as a **Reference (R)**, while the others are tuned to specific gas absorption lines (like CO2, Hydrocarbons, or CO) or specific temperature ranges. 3. **Reference Thermistor:** Because thermopiles measure the *difference* in temperature between the "hot" junction and the "cold" junction (the sensor body), an internal NTC thermistor is included to measure the absolute temperature of the sensor housing for accurate calibration. --- ### 3. Connection & Integration The TO-39 package typically features several pins for the multi-channel output. * **Signal Conditioning:** The output voltage is very low. An external **Low-Noise Operational Amplifier** (Op-Amp) or a specialized **Instrumentation Amplifier** is required to boost the signal before it reaches an Analog-to-Digital Converter (ADC). * **Common Ground:** Usually, all four thermopile channels share a common ground pin to simplify wiring. --- ### 4. Primary Applications Thanks to its quad-channel design, this component is used in: * **NDIR Gas Sensing:** Identifying multiple gases simultaneously (e.g., CO2, CH4, and CO). * **Industrial Pyrometry:** Multi-wavelength temperature measurement for surfaces with varying emissivity. * **Medical Equipment:** Anesthesia monitoring or capnography. ---