TOS series detect the current induced by a stray capacitance of the test lead.
(Stray capacitance is also known as a parasitic capacitance.)
As for the test leads of TOS series, there is a likelihood of a capacitance effect between the high-voltage and low-voltage test leads.
The user’s manual of TOS series describe the details of the current flowing through the stray capacitance.
The typical current values are as follows: output voltage 1 kV: 16 μA, 2 kV: 32 μA.
This current will increase with the twisted test leads.
Since the stray capacitance is an inevitable phenomenon, when performing high-sensitivity and high-accuracy measurements, consider adding the above value into the upper and lower limits of the test.
TOS9200/TOS9300 series have the offset cancel function to cancel the current flowing through the stray capacitance.
