Kikusui TOS9200, Руководство по эксплуатации

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TOS9200/9201 Basic Operations 3-27
• With the timer ON, if the wait time thus set exceeds the sum of the voltage rise
time and the test time, “OVER WAIT” fl ashes on the LCD to indicate that testing
cannot be performed.
Setting LOW/GUARD for the GND
You can select either of the following two measurement modes;
the LOW mode that the GND is connected to the tester’s LOW terminal,
the GUARD mode that the GND is used as guard.
In both modes, the tester detects the current fl owing into the LOW terminal from the
HIGH VOLTAGE terminal via the DUT. In the LOW mode, the LOW terminal is
connected to the chassis. This leads to the problem of the insulation resistance
between the test leadwire and jigs and the earth being included in the measurement.
Nonetheless, the GND mode ensures safe testing, as it does not short-circuit the
ammeter.
In the GUARD mode, on the other hand, only the current
fl owing into the LOW ter-
minal from the HIGH VOLTAGE terminal via the DUT is measured, while the in fl u-
ence of the insulation resistance between the earth and the test leadwire and jigs is
eliminated. For this reason, the GUARD mode is effective in measurements that
require high sensitivity and high accuracy. At the same time, however, the ammeter
can be short-circuited, posing a grave danger if the LOW terminal and the chassis
are short-circuited when part of the DUT is connected to an earth ground.
If it is not known whether the DUTs and jigs are grounded, select the LOW mode.
To switch between the two modes, use the SHIFT + F3 keys, regardless of the loca-
tion of the cursor. Each time the SHIFT + F3 keys are pressed, LOW and GUARD
alternate.
Using the keys, move the cursor to the right of GND; settings can then be
made using the rotary knob.
Turn the rotary knob clockwise: GUARD
Turn the rotary knob counterclockwise: LOW
When LOW is selected, the LED to the left of the LOW terminal lights up.
NOTE
DCW2 DCW2
START : 10%
RISE : 0.1s (– – – V/s)
GND : LOW
WAIT : 0.3s
F1 F2 F3 F4 F5
SHIFT
GND
LED lights up