Pen /Short Compensation - BK Precision 885 Manual De Instrucciones

H H L L H H L L
CUR POT POT CUR CUR POT POT CUR
Cd
Guard
Plant
DUT
Connection
Point
C C
h l
Ground
(b) Guard Plant reduces
(a) Parastic Effect
Parastic Effect
Figure 3.6
4.2 Open/Short Compensation
For those precision impedance measuring instrument, the open and
short compensation need to be used to reduce the parasitic effect of
the test fixture. The parasitic effect of the test fixture can be treated
like the simple passive components in figure 3.7(a). When the DUT
is open, the instrument gets the conductance Yp = Gp + jCp
(Figure 3.7(b)). When the DUT is short, the instrument gets the
impedance Zs = Rs + jLs (Figure 3.7(c)). After the open and short
compensation, Yp and Zs are for calculating the real Zdut (Figure
3.7(d)).
34