load cell excitation voltage

When you look at a load cell datasheet, excitation voltage is listed as a recommended range, sometimes with a maximum value. Exceeding that maximum can permanently damage the strain gauge bridge. But even staying inside the recommended band requires care. A 10 V excitation on a 350 Ω bridge yields about 28 mA of current, which causes self-heating. For high-precision geotechnical instruments, that temperature rise can introduce errors that take minutes to stabilize. Kingmach offers sensors with various bridge resistances and compensation methods to minimize such effects. Many of our load cells for tunnel monitoring and foundation testing accept 5–15 V DC, giving you flexibility when connecting to data loggers or PLCs that may only supply a fixed 10 V or 12 V rail. We also stock models with built-in signal conditioning that regulate the excitation internally, so the external supply can vary within a wide range while the bridge sees a stable reference. This design saves you from buying a separate precision power supply. Another practical point: long cable runs act like antennas. Higher excitation voltage helps improve the signal-to-noise ratio because the output is proportionally larger. But you need to ensure the cable resistance does not drop too much voltage before reaching the load cell. With a 4-wire system, you can sense the actual voltage at the sensor and compensate. Our technical notes on wiring give clear examples. For any project, we recommend testing the setup with the actual cable length to confirm the excitation at the sensor terminals. If you need custom voltage ranges or want to discuss the best power strategy for your monitoring network, our team can review your requirements. We frequently ship to integrators who appreciate that we cannot only supply the load cells but also the compatible signal conditioners and accessories, ensuring the entire measurement chain works together. This avoids the blame game when one component is not quite right.