The **PS87-503P-B-R2** is a high-precision, solid-state pressure switch/gauge manufactured by Nidec Components (formerly Copal Electronics). It is designed for industrial automation and pneumatic applications where reliable monitoring of air pressure is required. ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Pressure Type** | Gauge Pressure | | **Rated Pressure Range** | 0 to 5.0 MPa (approx. 725 PSI) | | **Output Type** | 2 NPN Open Collector Outputs + Analog Output | | **Analog Output** | 1 to 5 V DC | | **Power Supply** | 12 to 24 V DC ± 10% | | **Display** | 3.5 digit Red LED | | **Pressure Port** | R 1/4 (Tapered pipe thread) | | **Ingress Protection** | IP65 | --- ### 2. Electronic Components & Functionality The device integrates several electronic layers to convert physical pressure into readable data and switching signals: #### A. Sensing Element (Diffused Silicon) The heart of the unit is a **piezoresistive silicon diaphragm**. When pressure is applied, the diaphragm deforms, changing the electrical resistance of the bridge circuit diffused into the silicon. This provides high sensitivity and long-term stability compared to mechanical switches. #### B. Signal Conditioning (ASIC) The low-level signal from the sensor is processed by an internal **Application-Specific Integrated Circuit (ASIC)**. This chip performs: * **Amplification:** Boosting the micro-volt signals. * **Temperature Compensation:** Correcting errors caused by environmental temperature changes. * **Linearization:** Ensuring the output is directly proportional to the pressure. #### C. Control & Output Circuitry * **Comparator/Microcontroller:** Compares the current pressure against user-defined "Set Points." * **Transistor Outputs (NPN):** The "P-B" in the model name indicates NPN open collector outputs. These act as electronic switches to trigger PLCs or relays when pressure thresholds are met. * **Analog Buffer:** Outputs a continuous 1-5V signal for remote monitoring or data logging. --- ### 3. Wiring Configuration The device typically uses a 5-wire interface to manage power and signals: ```markdown Color Code | Function -----------|----------------------- Brown | Power (+) 12-24V DC Blue | Power (-) Common/GND Black | Switch Output 1 (NPN) White | Switch Output 2 (NPN) Gray | Analog Output (1-5V) ``` --- ### 4. Application Use Cases * **Pneumatic Systems:** Monitoring compressor tank pressure. * **Leak Detection:** Using the high sensitivity to detect pressure drops in sealed systems. * **Industrial Robotics:** Ensuring vacuum or air pressure is sufficient for end-of-arm tooling (EOAT) safety.