| 摘要 |
PURPOSE:To make it possible to adjust resistors at the same time with the adjustment of strain gages, by forming the resistors, which determine the gain of a signal amplifier, on a pattern forming surface by thin film technology. CONSTITUTION:The gain of a signal amplifier 16 is expressed by 1+R12/R11. There is dispersion is sensitivity of a load cell part 13. Even if the value of R12/ R11 is the same with respect to the same load, dispersion is present in an output voltage V30 of the amplifier 16. Then, it is necessary to adjust the gain of the amplifier 16 with respect to the sensitivity of the load cell part 13 in order to make the voltage V30 the specified value. Therefore, the resistors R11 and R12 are formed in the same pattern by thin film technology just like strain gages R5-R8. The resistors R11 and R12 of the amplifier 16 are adjusted by laser trimmers at the same time as the adjustment of the strain gages R5-R8 of the load cell part 13. When the applied load to the load cell part 13 is the initial value, an output voltage V20 of a zero-point setter 15 is adjusted by resistors R9 and R10 of the zero-point setter 15 so that the output voltage V30 of the amplifier 16 becomes the specified value. The resistors R9 and R10 can be adjusted by laser trimmers at the same time with the adjustment of the strain gages R5-R8. |
