MR8740T_Quick guide_eng_20191016H.pdf - 第19页
13 Operation Precautions IMPORT ANT • Install a blank panel over the slot with no module installed. If the measurement is performed without the blank panel installed, the instrument may not work as specied because of te…
12
Operation Precautions
DANGER
It is recommended to measure the secondary side of a distribution panel with
the U8974 High Voltage Unit. Do not measure the primary side of the distribution
panel because an unrestricted current ow could damage the instrument and
facilities if a short circuit occurs.
• Each channel of Model U8979 Charge Unit has the BNC terminal and miniature
connector terminal with the common ground. Do not connect cables with each
of the terminals simultaneously to avoid a short-circuit.
WARNING
• To avoid an electric shock and damage to the module and the instrument,
conrm that the instrument is turned off and that the connection cords are
disconnected before removing or replacing a module.
• To avoid an electric shock, install a blank panel over any slot with a module
removed.
• To prevent the instrument damage or an electric shock, use only the screws that
are originally installed for securing the module in place. If you have lost any
screws or nd that any screws are damaged, please contact your authorized
Hioki distributor or reseller.
CAUTION
• Do not touch module connectors inserted to the instrument to avoid damaging a
module.
• To avoid damage to the instrument, do not unplug the power cable from the
instrument when operations are in progress. Be sure to use the power key to turn off
the instrument.
• The U8794 permits a load resistance of 1 k
Ω
or more while outputting a voltage. Do
not connect a load resistance lower than the permissible value or short-circuit an
output terminal. Damage to the instrument could result.
• Do not set the OUTPUT terminal status of the U8794 to SHORT when a power supply
unit connects with the OUTPUT terminal. A short-circuit current will ow, resulting in
damage to the instrument or power supply device.
• Do not connect anything with the U8794 OUTPUT terminal during a general test
of the self-diagnosis function and an offset measurement of the offset canceling
function. When the connected target is a power supply device, the instrument and the
connected target can be damaged because the OUTPUT terminals of each channel
are momently short-circuited.
• The mounting screws must be rmly tightened or the module may not work as
specied, or may even fail.
• When you use the U8794 resistance generation function to presume a characteristic
of a connected target with an output resistance of less than 1 k
Ω
, a current that
exceeds the specication will ow, resulting in damage to the instrument and the
connected target.
• Model U8979 Charge Unit has two miniature connectors with the maximum input
charge of ±500 pC (for six higher-sensitivity range) or ±50,000 pC (for six lower-
sensitivity range). Inputting a charge that exceeds these value causes damage to the
instrument.
• Use an acceleration sensor with a built-in pre-amplier that conforms to the
specication of Model U8979 (3.5 mA, 22 V). Using a inapplicable sensor may cause
damaging itself.
13
Operation Precautions
IMPORTANT
• Install a blank panel over the slot with no module installed. If the measurement is performed
without the blank panel installed, the instrument may not work as specied because of
temperature instability within the modules.
• If any unexpected waveform is observed or a module is not recognized, send the instrument for
repair.
• Disconnect all cables and remove a USB ash drive before carrying the instrument.
• Waveforms can frequently uctuate even when no voltage is applied due to an induction voltage.
This, however, is not a malfunction.
• This instrument may cause interference if used in residential areas. Such use must be avoided
unless the user takes special measures to reduce electromagnetic emissions to prevent
interference to the reception of radio and television broadcasts.
Precautions during shipment
CAUTION
To avoid damage to the instrument, protect it from physical shock when transporting
and handling. Be especially careful to avoid physical shock due to dropping it.
• Store the packaging materials even after unpacking, because you will need them when you
transport the instrument.
• To ensure safe handling, when transporting the instrument, please use the original box and
packing materials,
but do not use if the box is damaged or warped, or if the packing materials are in poor condition
or incomplete.
If you nd any damage, contact your authorized Hioki distributor or reseller.
• When packing the instrument, make sure to disconnect the test leads and power supply cords
from the main device.
• When transporting, avoid dropping or other excessive impact.
CD precautions
• Exercise care to keep the recorded side of discs free of dirt and scratches. When writing text on a
disc’s label, use a pen or marker with a soft tip.
• Keep discs inside a protective case and do not expose to direct sunlight, high temperature, or
high humidity.
• Hioki is not liable for any issues your computer system experiences in the course of using this
disc.
14
Operation Precautions
Handling storage devices
CAUTION
• Do not carry the instrument with a USB ash drive inserted. Damage could result.
•
Do not subject the instrument to extreme shock or vibration. Shock can cause damage to
the built-in SSD unit.
• Do not insert a storage device upside down, backward, or in the wrong direction.
Doing so may damage the storage device or instrument.
Exercise care when using such products because static electricity could damage the
external storage device or cause a malfunction of the instrument.
IMPORTANT
• Do not extract any external storage device or turn off the instrument while the instrument is
accessing the storage device (while the green DIAG LED is lighting up). Data stored in the
device could be lost.
• No compensation is available for loss of data stored on the external storage device (USB ash
drive) or the built-in SSD unit of the instrument, regardless of the content or cause of damage
or loss. Be sure to back up any important data stored on the device (USB ash drive) and the
built-in SSD unit of the instrument.
• When the instrument is left powered off for a long period of time (about 1 year or more), the
data saved to the built-in SSD may be lost. Be sure to back up the data if the instrument is to
be left powered off for a long time.
• With some external storage device, the instrument may not start up if power is turned on while
the device is inserted. In such a case, turn off and cycle the instrument.
• The instrument supports not all commercially available USB ash drives.
• The number of times data can be written on external storage devices (USB ash drive) and the
built-in SSD unit of the instrument is limited by their ash memory. If data has been rewritten
many times, data reading and writing capabilities will be degraded. In that case, replace the
device.
• Model Z4006 USB Drive can be used to save data. Use the product available as Hioki’s option
only. (p. 5)