The **115-R** typically refers to a high-precision, wirewound resistor series, most notably associated with manufacturers like **Ohmite** or **TE Connectivity**. These parts are designed for high stability and reliability in demanding environments. --- ### 1. Key Technical Specifications The following table highlights the general characteristics of a standard 115-R series resistor: | Specification | Typical Value / Range | | :--- | :--- | | **Resistance Range** | 0.1Ω to 1MΩ | | **Tolerance** | ±0.01% to ±1% | | **Temperature Coefficient** | ±2 ppm/°C to ±10 ppm/°C | | **Power Rating** | 0.25W to 1W (varies by physical size) | | **Material** | Wirewound (Nichrome or similar alloy) | | **Mounting Type** | Through-hole (Axial or Radial) | --- ### 2. Physical Construction The "115" designation often refers to the physical package size or series family, while the "R" usually denotes a specific feature (like "Radial" lead configuration or "RoHS" compliance). * **Core:** Usually a high-grade ceramic or epoxy. * **Winding:** Precision alloy wire wound in a non-inductive pattern to minimize interference. * **Coating:** Encapsulated in a moisture-resistant epoxy or silicone molding to protect against environmental degradation. --- ### 3. Common Applications Due to their high precision and low drift, these parts are not found in consumer electronics but rather in specialized fields: 1. **Metrology:** Standard lab equipment requiring exact resistance values. 2. **Medical Equipment:** Monitoring devices where signal accuracy is critical. 3. **Aerospace:** High-reliability circuits that must withstand temperature fluctuations. 4. **Audio Equipment:** High-end pre-amplifiers where thermal noise must be minimized. --- ### 4. Part Number Breakdown Example If you are looking at a specific manufacturer code like `115-R10-JB`, it often translates as: * **115:** Series/Size. * **R10:** Resistance value (0.10 Ohms). * **J:** Tolerance code (e.g., ±5%). * **B:** Packaging type (Bulk).