The base mounting surface of the load cell should be flat

To ensure a high-precision test system, in addition to using a high-precision A/D converter, the design of other modules in the system also has a great impact on the accuracy of the entire system.

(1) The sensor is the core of the entire system. To obtain a reliable data source, attention must be paid to the installation method of the resistance load cell. The base mounting surface of the load cell should be flat and clean, without any oil film, glue film, etc. The installation base requires higher strength and rigidity than the sensor itself. The installation surface of the installation base should be leveled with a spirit level. Ordinary flat washers cannot be used during installation, spring washers should be used. When loading the sensor with force, load according to the direction of the sensor loading force to avoid lateral or additional torque force.

(2) Independent power supply for digital devices and analog devices, stabilize the power supply, and add a filter circuit to prevent power supply noise from affecting the system. In order to prevent conductive high-frequency electromagnetic interference, shield beads are added to the sensor signal output terminal and power line. Try to isolate the digital part from the analog part, and isolate the digital ground from the analog ground when wiring the PCB.

The system can run stably, the measurement results meet the accuracy requirements, and the display resolution is 1/40 000. The data stabilization time is less than 1 s.