The **2TT-70-R** is a specific type of high-precision, sub-miniature temperature sensor, often classified under the category of **RTDs (Resistance Temperature Detectors)** or specialized thermal probes. These are commonly used in industrial monitoring, aerospace, and laboratory equipment. --- ### 1. General Specifications The 2TT-70-R typically follows the characteristics of a **Platinum RTD (Pt100 or Pt1000)** based on its naming convention and standard industry usage. | Feature | Description | | :--- | :--- | | **Sensor Type** | Resistance Temperature Detector (RTD) | | **Material** | Platinum (Pt) | | **Nominal Resistance** | Usually 100 $\Omega$ at 0°C (Standard) | | **Tolerance Class** | Class A or Class B (High Accuracy) | | **Configuration** | 2-wire or 3-wire lead configuration | | **Body Material** | Stainless Steel or Ceramic casing | --- ### 2. Key Electronic Components The device is composed of three primary electronic elements: 1. **Sensing Element:** A thin-film platinum layer deposited onto a ceramic substrate. Its electrical resistance increases linearly with temperature. 2. **Lead Wires:** Usually made of silver-plated copper or nickel, insulated with Teflon (PTFE) or Kapton to withstand high temperatures. 3. **Encapsulation:** A protective "sheath" that prevents moisture and chemicals from damaging the platinum element. --- ### 3. Operating Principle The 2TT-70-R operates based on the **Callendar-Van Dusen equation**. As the temperature of the environment changes, the physical properties of the platinum element change: * **Positive Temperature Coefficient (PTC):** As temperature goes **UP**, resistance goes **UP**. * **Measurement:** A small constant current (typically 1mA) is passed through the sensor, and the voltage drop is measured to calculate the exact temperature. --- ### 4. Technical Performance | Parameter | Typical Value | | :--- | :--- | | **Temperature Range** | -70°C to +260°C (depending on insulation) | | **Stability** | Drift < 0.05% per year | | **Response Time** | Fast (due to sub-miniature size) | | **Insulation Resistance** | > 100 M$\Omega$ at 100V DC | --- ### 5. Common Applications * **HVAC Systems:** Precision air temperature monitoring. * **Medical Devices:** Monitoring internal equipment temperatures. * **Industrial Automation:** Overheat protection for small motors or circuit boards.