The **ADN-131-R/Q** refers to a high-performance **Differential Pressure Switch** or **Differential Pressure Transmitter**, typically used in HVAC, industrial ventilation, and cleanroom monitoring applications. Below is a detailed breakdown of its electronic components and technical specifications. --- ## 1. Core Technical Specifications The device is designed to measure the pressure difference between two points and convert that mechanical force into an electrical signal. | Feature | Description | | :--- | :--- | | **Sensing Element** | Piezo-resistive silicon sensor or high-sensitivity diaphragm | | **Output Signal** | 4-20 mA (current loop) or 0-10 VDC (voltage) | | **Power Supply** | Usually 24V AC/DC (standard industrial voltage) | | **Pressure Range** | Varies by model (e.g., 0-100 Pa up to 0-5000 Pa) | | **Electrical Connection** | Screw terminals for wire gauges 1.5mm² | | **Accuracy** | Typically ±1.0% to ±1.5% of full scale | --- ## 2. Electronic Component Breakdown ### A. The Transducer/Sensor Unit The heart of the ADN-131 is the **MEMS (Micro-Electro-Mechanical Systems)** pressure sensor. * **Function:** When air pressure pushes against a silicon diaphragm, it changes the electrical resistance of the circuit (piezoresistive effect). * **Benefit:** High stability and low hysteresis, meaning it returns to zero accurately. ### B. Signal Conditioning Circuitry The raw millivolt signal from the sensor is too weak for industrial controllers (PLCs). The internal electronics include: * **Amplifier:** Boosts the weak sensor signal. * **ADC (Analog-to-Digital Converter):** Some models process the signal digitally for temperature compensation. * **DAC/Output Stage:** Converts the signal back to a standardized **4-20mA** or **0-10V** signal to resist electromagnetic interference (EMI) over long cable runs. ### C. Protection Electronics To ensure longevity in industrial environments, the PCB (Printed Circuit Board) includes: * **Reverse Polarity Protection:** Prevents damage if the power wires are connected backward. * **Overvoltage Protection:** Guards against spikes in the power supply. --- ## 3. Wiring Configuration Most ADN-131 models utilize a 3-wire or 2-wire configuration depending on the output type. ```mermaid [Power Supply +24V] ----> [Terminal 1: V+] [Common/Ground] ----> [Terminal 2: GND] [Output Signal] ----> [Terminal 3: Out (0-10V / 4-20mA)] ``` --- ## 4. Common Applications * **Filter Monitoring:** Measuring the pressure drop across air filters to signal when they are clogged. * **Cleanrooms:** Maintaining a positive pressure relative to the outside to prevent contamination. * **Fan Control:** Monitoring duct pressure to adjust Variable Frequency Drives (VFDs). ---