Low-cost piezoresistive silicon load cell independent of force distribution

摘要

A silicon load cell (force sensor) is presented which isudbased on a new operating principle. The force is measuredudby compressing a meander like strain gage. A secondudstrain gage which is not loaded, is used for temperatureudcompensation and for compensation of bending andudstretching stresses in the chip. Also, same changes in zeroudload resistor values are eliminated. It is shown that theudoutput of the bridge is a linear function of the total forceudand independent of the force distribution on the siliconudchip. Measurements up to 1000 kg show a linear responsudand a short term repeatability which is within 0.1 %.udCreep after 30 minutes is within 1.2 %.