Hioki DSM-8542, Instruction Manual, Page: 70 / 140

60
[Notice]
The following conditions are needed for an external trigger signal:
Pulse width 100
μ
s or more
Signal logic Negative logic (active low)
Drive output Open collector or TTL output
Drive current Sync current of more than 1mA
[Caution]
When changing the measuring terminal by a relay while outputting measuring
voltage, serially insert a protective resistance to limit the current passing
through the contact to not exceed the maximum permissible current of the
contact, for protection of the relay contact.
Protective resistance value
≥
(measuring voltage)/(maximum permissible current)
The meter is equipped with a contact check function that checks connection (contact) of
the sample and measuring circuit including a jig and other devices to enhance reliability
of insulation resistance measurement of samples with a large electrostatic capacity such
as capacitors. For more information, refer to 6.7.2 “Contact check.”
Measuring time can be shortened and measurement accuracy can be enhanced by taking
measurement after charging a sample in advance when automatically measuring a
sample of a large electrostatic capacity such as a capacitor.
The power supply unit of the meter is an external unit. HIOKI’s dedicated power supply
unit PSU
- 8541 (option) has a charging current source of 20 circuits specifically for this
purpose.
The necessary settings for the dedicated power supply unit PSU-8541 can be set on the
Setting screen of the meter when PSU-8541 is connected to it. Separate settings are
needed when a current source for charging is connected.
Move to the “POWER SOURCE SELECT” screen by keying [SETUP] [F4] (POWR) and
set a current limiter set value “CURL IC:” to 5, 10, 25 or 50mA. Setting to other than “0”
will light up the side mark for “CHARGE ON” on the left of the screen. The charging
current source can be set with all 20 channels.