The **FRTD-R-F3-P** is a high-precision Platinum Resistance Temperature Detector (RTD) sensor, typically used in industrial automation, HVAC, and laboratory environments. It belongs to the thin-film RTD family, specifically utilizing a **Pt100** or **Pt1000** element. --- ### 1. Key Technical Specifications | Feature | Description | | :--- | :--- | | **Sensor Type** | RTD (Resistance Temperature Detector) | | **Material** | Platinum (Pt) | | **Resistance at 0°C** | 100 $\Omega$ (Standard) or 1000 $\Omega$ | | **Temperature Range** | -50°C to +400°C (standard range) | | **Tolerance Class** | Class A or Class B (per IEC 751) | | **Connection Type** | 3-Wire Configuration (F3) | | **Form Factor** | Probed/Encapsulated for moisture resistance | --- ### 2. Breakdown of the Model Code The part number can be broken down to understand its electronic behavior: * **FRTD:** Flexible/Film-based Resistance Temperature Detector. * **R:** Represents the sensor element type (Resistance-based). * **F3:** Indicates a **3-wire** lead configuration. This is crucial for electronic circuits as it allows for the compensation of lead wire resistance, ensuring higher accuracy over long distances. * **P:** Denotes **Platinum** as the sensing material, which provides the highest linearity and stability over time compared to Nickel or Copper. --- ### 3. Electronic Operating Principle The device operates on the principle that the electrical resistance of platinum increases predictably as temperature rises. The relationship is governed by the Callendar-Van Dusen equation: ```python # Simplified Linear Approximation for RTD # R(t) = R0 * (1 + A * t) R0 = 100.0 # Resistance at 0 degrees Celsius Alpha = 0.003851 # Standard temperature coefficient for Platinum def calculate_resistance(temp): return R0 * (1 + Alpha * temp) # Example: Resistance at 100°C # R(100) = 100 * (1 + 0.003851 * 100) = 138.51 Ohms ``` --- ### 4. Typical Application Circuit To interface this part with a microcontroller (like an Arduino or PLC), the following electronic components are usually required: 1. **Constant Current Source:** To prevent "self-heating," a low current (typically 1mA) is passed through the RTD. 2. **Wheatstone Bridge:** Used to detect small changes in resistance. 3. **Instrumentation Amplifier:** Amplifies the millivolt-level signal to a readable 0-5V or 4-20mA range. 4. **ADC (Analog to Digital Converter):** High-resolution (16-bit or 24-bit) ADCs like the MAX31865 are often used specifically for these 3-wire sensors.