Agilent Technologies 4349B, Руководство пользователя

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4349B
Precharge Time and W ait Time
When setting up the system for measuring the insulation resistance of capacitors , consider the
precharge time and the wait time .
Note
The precharge time of an ideal capacitor is described in this section. Generally ,
you should consider characteristics of a dielectric for the estimation of the
actual precharge time .
Precharge time
Figure 6-7. Precharge Time
When the capacitor is charged through precharge register Rp , the precharge time t
p
is
calculated as follows (where , Rx Rp):
t
p
= 0C
x
2 R
p
2 l nK
where , C
x
: Capacitance value [F]
K : (T est voltage 0 Charge voltage) / T est voltage
F or example , when Rp is 1 k (=10
3
), Cx is 1 F (=10
06
F), and K is 0.1, the precharge
time is ,
t
p
= 010
06
2 10
3
2 l n0: 1
= 2: 3[ms ]
In this example , one precharge stage is enough because t
p
is less than the measurement time .
6-12 Application Measurement