## Overview of the 24PC01SMT Pressure Sensor The **24PC0100G2** (commonly associated with the Honeywell 24PC series) is a miniature, unamplified, piezoresistive pressure sensor. It is designed for measuring gauge pressure in medical, environmental, and industrial applications. --- ### 1. Technical Specifications Below are the primary electronic and physical characteristics of the 24PC series: | Characteristic | Specification | | :--- | :--- | | **Pressure Type** | Gauge (measures relative to atmospheric pressure) | | **Pressure Range** | 0 to 100 psi | | **Bridge Type** | Wheatstone Bridge | | **Output Type** | Analog (Unamplified/Millivolt) | | **Excitation Voltage** | 10 VDC (Typical), 12 VDC (Max) | | **Sensitivity** | 1.0 mV/psi (Typical) | | **Operating Temperature** | -40°C to 85°C | | **Linearity Error** | ±0.5% to ±1.0% | --- ### 2. Internal Electronic Structure The device operates using a **Piezoresistive Silicon Chip**. When pressure is applied to the diaphragm, the resistance of the embedded resistors changes. #### The Wheatstone Bridge * The sensor uses a **four-resistor Wheatstone bridge** configuration. * **Input:** Voltage is applied across the bridge. * **Output:** As pressure changes, the bridge becomes unbalanced, resulting in a small millivolt (mV) output signal proportional to the pressure. --- ### 3. Pin Configuration Most sensors in this series use a 4-pin layout: 1. **Pin 1:** Supply Voltage ($V_{s}+$) 2. **Pin 2:** Output ($V_{out}+$) 3. **Pin 3:** Ground ($GND$) 4. **Pin 4:** Output ($V_{out}-$) --- ### 4. Application Requirements Because the 24PC0100G2 is an **unamplified** sensor, it requires specific peripheral electronics to be useful in a digital system (like an Arduino or PLC): * **Instrumentation Amplifier:** The output is in millivolts (very low). You must use an amplifier (e.g., AD620 or INA126) to boost the signal to a 0-5V range. * **ADC (Analog to Digital Converter):** A high-resolution ADC (12-bit or higher) is recommended for accurate pressure readings. * **Voltage Regulation:** Since the output is proportional to the input voltage (ratiometric), a stable, noise-free power supply is critical for precision. --- ### 5. Common Use Cases * **Medical:** Blood pressure monitoring, oxygen concentrators. * **Industrial:** HVAC systems, water level sensing. * **Automotive:** Transmission fluid pressure, engine oil pressure.