Point detail

Fourth step

If V1 is greater than or equal to V2, insert a standard known resistance (Ro) between the negative pole of the tested-device and the ground connection. With Ro installed, measure the voltage (V1 ') between the negative pole of the tested-device and the ground connection (see Figure 2).

 Calculate the electrical isolation (Ri) according to the following formula:

Ri = Ro*(Vb/V1 ' - Vb/V1) or Ri = Ro*Vb*(1/V1 ' - 1/V1)

Figure 2