The **47LM-100R-R/Q** is a specific variant of a high-performance **Linear Variable Differential Transformer (LVDT)** sensor, typically manufactured by measurement specialist companies like Measurement Specialties (TE Connectivity). These devices are used for precision linear displacement measurements in industrial and aerospace environments. --- ### 1. Key Technical Specifications The part number breakdown identifies the following electrical and mechanical characteristics: | Feature | Specification | Description | | :--- | :--- | :--- | | **Type** | LVDT | Linear Variable Differential Transformer | | **Range** | ± 0.100 Inches | The total linear travel range of the core | | **Input Voltage** | 3.0 Vrms (Nominal) | The AC excitation voltage required | | **Operating Freq.** | 400 Hz to 10 kHz | Range of AC frequency for the primary coil | | **Linearity** | < ± 0.25% FS | High precision relative to the full scale | | **Body Diameter** | 0.75 Inches (19mm) | Standard industrial form factor | --- ### 2. Functional Electronic Components The internal electronics of the 47LM-100R-R/Q consist of three primary induction coils wound around a hollow non-magnetic tube: 1. **Primary Coil:** Located in the center; it is energized with an AC reference signal. 2. **Secondary Coils (2):** Symmetrically positioned on either side of the primary. These are connected in **series-opposition**. 3. **Magnetic Core:** A movable ferromagnetic core (the "slug") that slides inside the coils. As the core moves, it alters the magnetic coupling between the primary and the two secondaries. ### 3. Electronic Operation Logic The device operates on the principle of **electromagnetic induction**: * **Null Position:** When the core is exactly in the center, the voltage induced in both secondary coils is equal and opposite, resulting in a **0V output**. * **Displacement:** As the core moves toward one end, the induction in that secondary coil increases while the other decreases. * **Phase Shift:** The phase of the output signal (relative to the primary) indicates the **direction** of movement, while the amplitude indicates the **distance**. --- ### 4. Application Environments Because the 47LM-100R-R/Q is an AC-operated LVDT, it contains no internal active electronics (like transistors or ICs). This gives it specific advantages: * **Temperature Resilience:** Can operate in extreme heat/cold where DC sensors would fail. * **Longevity:** No mechanical contact between the core and coils means zero friction and an almost infinite mechanical life. * **Signal Conditioning:** Requires an external **LVDT Signal Conditioner** (e.g., an AD598 or NE5521) to convert the AC output into a usable 0-10V or 4-20mA DC signal. ---