Calculate input capacitance in coulombs for 6514, 6517B.
The effective input capacitance in coulombs mode is the
feedback capacitor times the open loop gain of the input stage.
In both meters this gain is at least 4xE6.
The 20nC and 200nC ranges of the 6514 use a 1nF capacitor,
giving an effective capacitance of 4 milli farads.
The 2uC and 20uC ranges use a 100nF capacitor, and the effective
capacitance is 400 milli farads.
On the 2nC and 20nC ranges of the 6517A use a 100pF capacitor
giving an effective capacitance of 400uF.
The 200nC and 2uC ranges use a 10nF capacitor, giving an effective capacitance
of 40 milli farads.