This invention has, the capacitive return trance impedance operational amplifier (11) 1st input (121), 2nd input (122) and output (125) the starring calculation amplifier which it possesses (107) with, the integrating capacitor which is connected during 2nd inputting and output (106) with, the integrating capacitor (106) with the 1st switch which is connected in parallel (105) with regards the device which it has. The device has, furthermore, 3rd input (123) with 4th input (124) the automatic zero operational amplifiers which it possesses (110), the signal of hypothetical ground electric potential is input 3rd input (123) with 1st input (121) vis-a-vis. 4th input (124) the circuit (15) through, output (125) it is connected, the circuit (15), two offset error condensers (112,114) with the 2nd and 3rd switch (111,113) has.
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