Load Cell Considerations

A weight sensor is actually a device that converts a mass signal into a measurable electrical output. The first thing to consider when using a sensor is the actual working environment where the sensor is located, which is very important for the correct selection of the weight sensor. It is related to whether the sensor can work normally, its safety and service life, and even the reliability and safety of the entire weighing instrument. In the basic concepts and evaluation methods of the main technical indicators of the weight sensor, there are qualitative differences between the old and new national standards.

Folding Considerations

The signal cable of the sensor should not be arranged in parallel with the strong power supply line or control line (for example, do not put the sensor signal line and the strong power supply line and control line in the same pipe). If they must be placed in parallel, the distance between them should be kept above 50CM, and the signal lines should be covered with metal pipes.

In any case, the power line and the control line should be twisted together, and the degree of integration should be 50 rpm/m. If the sensor signal line needs to be extended, a special sealed cable junction box should be used. If this kind of junction box is not used, and the cable is directly connected to the cable (soldered end), special attention should be paid to the sealing and moisture-proof. The sensor should be recalibrated.

If the signal cable is very long and high measurement accuracy is to be ensured, a cable compensation circuit with a repeater amplifier should be considered.

Shielded cables should be used for all leads to or from the display circuit. The connection and grounding point of the shielded wire should be reasonable. If it is not grounded through the mechanical frame, it is grounded externally, but the shielded wires are not grounded after being connected to each other, and they are floating.

Note: There are 3 sensors that are all connected in parallel. The sensor itself is a 4-wire system, but it is replaced by a 6-wire connection method in the junction box.

The sensor output signal readout circuit should not be placed in the same box with equipment that can produce strong interference (such as thyristors, contactors, etc.) and equipment that generates considerable heat. If this cannot be guaranteed, it should be considered. A baffle is set between them to isolate them, and a fan is installed in the box.

The electronic circuit used to measure the output signal of the weight sensor should be equipped with an independent power supply transformer as much as possible, instead of sharing the same main power supply with equipment such as contactors.