What precautions should be taken when using load cells? The importance of load cells in industrial weighing systems is undeniable. So, do you know what precautions should be taken when using load cells?
1. Sensor signal cables should not be run parallel to high-voltage power lines or control lines (e.g., do not place sensor signal lines, high-voltage power lines, or control lines in the same conduit). If they must be run parallel, the distance between them should be at least 50 cm, and the signal lines should be encased in metal conduits.
2. Under all circumstances, the power cord and control cord should be twisted together at a twist rate of 50 revolutions per meter. If the sensor signal line needs to be extended, a specially designed sealed cable junction box should be used. If this type of junction box is not used, and cables are directly connected (soldered ends), special attention should be paid to sealing and moisture protection. After connection, the insulation resistance should be tested and must meet the standard (2000-5000 MΩ). If necessary, the sensor should be recalibrated.
3. If the signal cable is very long and high measurement accuracy is required, a cable compensation circuit with a repeater amplifier should be considered.
4. All wires leading to or from the display circuit should be shielded cables. The connections and grounding points of the shielding wires should be reasonable. If grounding is not achieved through the mechanical frame, then external grounding should be used, but if the interconnected shielding wires are not grounded, they will be floating. Note: Three sensors are connected in parallel. The sensors themselves are 4-wire, but they are converted to a 6-wire connection in the junction box.
5. The sensor output signal readout circuit should not be placed in the same enclosure as equipment that can generate strong interference (such as thyristors, contactors, etc.) or equipment that generates considerable heat. If this cannot be guaranteed, a baffle should be installed between them for isolation, and a fan should be installed inside the enclosure.
6. Electronic circuits used to measure the output signal of weight sensors should be equipped with independent power supply transformers whenever possible, and should not share the same main power supply with contactors or other equipment.
7. Weighing sensors should be handled with care, especially small-capacity sensors made of aluminum alloy elastomers. Any impact or drop can severely damage their metrological performance. For large-capacity resistance strain gauge weight sensors, which generally have a large self-weight, appropriate lifting equipment (such as hand chain hoists, electric hoists, etc.) should be used as much as possible during handling and installation.
The mounting surface of the sensor base should be flat, clean, and free of any oil film, adhesive film, or other similar substances. The mounting base itself should have sufficient strength and rigidity, generally exceeding that of the sensor itself.
