Microtest 8740 - High Voltage Setting Edit (HV)

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4.1.4 High Voltage Setting Edit (HV)
This function is the setting for DC insulation, test voltage for AC tolerance, frequency, time, specification,
and other items.
(1) Press [HV].
(2) The LCD screen will display as follows.
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(1) Please use the direction button sot move to the item you want to set.
(2) Enter your specification control standard value.
(3) Descriptions of the insulation and tolerance items are as follows:
AC Offset AC ZERO:
Used to deduct the small leakage current of the internal loop of the tester and on the test fixture in
order to measure more precise AC HIPOT leakage current.
DC Offset DC ZERO:
Used to deduct the equivalent insulation value of the internal loop of the tester and the text fixture in
order to test higher DC IR insulation.
Beware when using the two functions described above: The AC/DC offset value must be less than 1/4
of the test value; it must not be less than 1:1 under the worst case, and this means that the offset value
is the same as the test value signal size. Under poor environments, it is difficult for the offset value to
be provided steadily and used for extended periods of time.
The offset function can also be used to determine the condition of the fixture terminal. For production
engineers to import and use in stage analysis.
(1) Voltage
Set the test voltage value for DC insulation and AC tolerance; the DC voltage is 50V-1000V
(8740N/8740NA) or 50V-1500V (8740FA), and the AC voltage is 100V-700V (8740-NA) or 100-1000
(8740FA).
(2) Frequency
Set the test frequency; only the AC part can be set (50/60Hz), DC insulation: switches between
tolerance and insulation, which is switching the test specification type. The tolerance test specification
is uA and the insulation test specification is MΩ.