Based on the part number **RHP-20D-R02FYR**, this component belongs to the **RHP series** of industrial sensors, specifically a **Wall-Mount Humidity/Temperature Transmitter** manufactured by **Dwyer Instruments**. --- ## 1. Technical Specifications This device is designed to monitor environmental conditions and convert them into electrical signals for Building Automation Systems (BAS) or HVAC controllers. | Feature | Specification | | :--- | :--- | | **Relative Humidity Range** | 0 to 100% RH | | **RH Accuracy** | ±2% (indicated by the '2' in the suffix) | | **Temperature Sensor Type** | 10K @ 25°C Type III Thermistor | | **Output Signal (RH)** | 4-20 mA (Loop Powered) | | **Mounting Style** | Wall Mount (North American Style) | | **Filter Type** | Sintered Filter (Standard) | --- ## 2. Key Electronic Components & Wiring The "RHP" series utilizes high-performance integrated circuits to ensure long-term stability. ### Humidity Sensing Element The device uses a **Capacitive Polymer Sensor**. * **How it works:** The dielectric constant of the polymer layer changes as it absorbs water vapor. * **Signal Conditioning:** An onboard ASIC (Application Specific Integrated Circuit) converts this capacitance change into a linear current output. ### Temperature Component The **R02** designation indicates a specific passive thermistor: * **Type:** 10K Ohm @ 25°C NTC (Negative Temperature Coefficient). * **Curve:** Type III. * **Output:** Resistance (Passive), meaning the controller measures the resistance directly rather than a voltage/current signal. --- ## 3. Terminal Connection Diagram Below is a representation of how the electronic leads are typically configured: | Terminal | Label | Function | | :--- | :--- | :--- | | 1 | + | Power Supply (10-35 VDC) | | 2 | - | 4-20 mA Humidity Output | | 3 | T1 | Temperature Sensor Lead 1 | | 4 | T2 | Temperature Sensor Lead 2 | --- ## 4. Part Number Breakdown The nomenclature **RHP-20D-R02FYR** is decoded as follows: * **RHP:** Humidity/Temperature Transmitter Series. * **2:** 2% Accuracy. * **0:** Wall Mount. * **D:** 4-20 mA RH Output. * **R02:** 10K Ohm Type III Thermistor. * **FYR:** Custom/Specific revision or packaging (often signifies the North American wall plate design). ---