| 摘要 |
PURPOSE:To attain high precision of the device by the use of one reference contact point compensator by a constitution wherein a switch for short-circuiting is provided on the input side of an amplifier and a central processing device is made to perform the operation of the difference between an input signal value stored in a memory and a signal value at the time of closure of the switch for short-circuiting. CONSTITUTION:By opening the swtich S for short-circuiting and opening and closing the selecting switches 21-2n of an input selector 2 sequentially, an input signal is overlapped with compensating voltage by the reference contact point compensator 3, and the signal thus compensated is amplified by an amplifier 4, subjected to A/D conversion 5 and stored in the memory 7 by the central processing device 6. At this time, the switch S for short-circuiting is also closed every time when the input selector 2 makes a round and the reference voltage at this time is stored in the memory 7. By making the central processing device 6 perform difference operation subtracting the reference voltage for drift compensation from a measurement input signal stored in the memory 7, a correct measurement signal is obtained for every input signal and delivered to an indicator 9. |
