force sensor Strain is ubiquitous, because resistance is used everywhere sensor It is a solid, durable and reliable mechanical and electrical product. However, in order to ensure the test accuracy, there are still many problems to be paid attention to in use. What should be paid attention to when using force sensor? The following are nine aspects that must be noted in the use of force sensors:
1. Some "baffles" should be set around the force sensor as far as possible, and even covered with thin metal plate. In this way, it can prevent impurities from contaminating the force sensor and some movable parts, and this kind of "contamination" often makes the moving parts uncomfortable and affects the weighing accuracy. Whether there is motion discomfort in the system can be judged by the following methods. That is to add or reduce about one thousandth of the rated load on the scale platform to see if the display instrument has any reflection, indicating that the movable part is not "contaminated".
2. Shielded cables shall be used for all wires leading to or from the display circuit. The connection and grounding point of shielding wire should be reasonable. If it is not grounded through the mechanical frame, it is externally grounded, but the shield wires are not grounded after being connected with each other, which is floating in the air. Note: three force sensors are connected in full parallel. The force sensor itself is 4-wire system, but it is replaced by 6-wire connection in the junction box. The output signal readout circuit of the force sensor should not be placed in the same box as the device which can produce strong interference, such as silicon control, contactor, etc.) and the equipment with considerable heat generation. If this can not be guaranteed, a baffle plate should be set between them and a fan should be installed in the box. The electronic circuit used to measure the output signal of force sensor should be equipped with independent power supply transformer as far as possible, instead of sharing the same main power supply with contactor and other equipment.
They shall be protected from the electric stress caused by lightning stroke by welding the copper wire (about 50mm2). In the use of force sensor, it is necessary to avoid strong thermal radiation, especially the strong thermal radiation of one side.
4. Prepare for electrical connection (for example, the signal cable of the force sensor shall not be arranged in parallel with the strong current power line or control line (for example, do not place the signal line of the force sensor, the strong current power line and the control line in the same pipe). If they must be placed in parallel, the distance between them should be above 50cm, and the signal wires should be sheathed with metal tubes.
5. Try to use structural accessories with automatic positioning (reset), such as spherical bearing, spherical bearing, positioning fastener, etc. They prevent some lateral forces from acting on the sensor. It should be noted that some transverse forces are not caused by mechanical installation, such as the transverse force caused by thermal expansion, the transverse force caused by wind force, and the transverse force caused by the vibration of agitator on some vessel type weighing instruments are not caused by mechanical installation. Some of the weighing instruments must be connected to the accessories on the scale body (such as the conveying pipe of the container scale). We should make them as soft as possible in the direction of the sensor loading spindle, so as to prevent them from "eating" the real load of the sensor and causing errors.
6. Handle with care, especially the small capacity sensor made of alloy aluminum elastomer. Any impact and drop may cause great damage to its metering performance. For large capacity Load cell Generally speaking, it has a large self weight, so it is required to use appropriate lifting equipment (such as chain block, electric hoist, etc.) as far as possible during handling and installation. The mounting surface of the sensor base should be flat and clean without any oil film, adhesive film, etc. The mounting base itself should have enough strength and rigidity, which is generally higher than that of the sensor itself.