Patent ID: 8354847

Claim:
An electrometer, comprising: a high gain differential amplifier having a first input, a second input, and an output; a first capacitor having a first terminal and a second terminal; said first terminal of said first capacitor is connected to said first input of said high gain differential amplifier; said second terminal of said first capacitor is connected to said output of said high gain differential amplifier; a first switch having a first terminal and a second terminal; said first terminal of said first switch is connected to said first input of said high gain differential amplifier; said second terminal of said first switch is connected to said output of said high gain differential amplifier; a second capacitor having a first terminal and a second terminal; said first terminal of said second capacitor is connected to said first input of said high gain differential amplifier; a second switch having a first terminal and a second terminal; said first terminal of said second switch is connected to said second terminal of said second capacitor; said second terminal of said second switch is connected to said output of said high gain differential amplifier; and said second input of said high gain differential amplifier is connected to ground potential.