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3. Precautions on the Samples
3.1 Static Electricity
3.2 Magnetism
3.3 Absorption/
Evaporation of
Moisture
3.4 Sample
Temperature
Generally speaking, objects made of synthetic resin and glass have high electric
insulating properties and, therefore, are apt to be electrically charged.
Measuring a charged sample as is may cause unstable indications, with resultant
poor reproducibility of the results. With this in mind, be sure to discharge
charged samples before measurement.
A sample affected by magnetism indicates different weight values depending on
where it is located on the measuring pan, along with resultant poor
reproducibility of the results.
When a magnetized sample must be measured, first demagnetize it or place an
appropriate pedestal on the measuring pan to adequately separate the
mechanism part of the balance from the magnetized sample for avoiding the
effects of magnetism.
Measuring a sample with moisture absorbed or evaporated (volatized)
continuously increases or decreases the values indicated. In such case, measure
the sample in a container with a small opening and sealed airtight with a cap.
A difference in temperature between a sample and the interior of a windshield
may cause convection to occur inside the windshield, resulting in erroneous
measurement. Therefore, measure a very hot or cold sample only after allowing
time for its temperature to acclimatize to room temperature. Moreover, to
prevent convection inside the windshield, allow time for the interior of the
windshield to acclimatize to room temperature.
The body heat of a person conducting measurement can also affect measurement
results. Avoid holding the sample with bare hands, and use long tweezers or a
similar tool instead. Also refrain from putting your hands inside the windshield
while measurement is in progress.
4. Precautions on the Main Unit of the Balance
4.1
Precautions on
Use
4.2 Calibration
4.3 Maintenance
• The balance is supplied with a transparent dust cover. The dust cover may be
statically charged immediately after removal from the packing box or under low
humidity conditions. Unstable indications by the balance may be due to
statically charged dust cover. In such case, wipe the dust cover with a damp
cloth or use a commercial antistatic agent. Otherwise, simply operate the
balance with the dust cover removed.
• To achieve more accurate weighing, wait at least 30 minutes after switching on
the balance in order to ensure that electricity is fully charged, then use the
balance only after loading it several times with an object of weight equal to the
weighing capacity.
• Periodically calibrate the balance to ensure accurate measurement at all times.
• For more precise calibration, use an external calibration weight that
approximates the weighing capacity. Moreover, calibrate the balance only after
allowing time for proper acclimation to ambient temperature following power-up.
• Wait at least 30 minutes after switching on the balance in order to ensure that
electricity is fully charged, then perform calibration only after loading the
balance several times with an object of weight equal to the weighing capacity.
Calibration is also required in the following cases:
• When operating the balance for the first time,
• When not using the balance for a long time,
• When relocating the balance, or
• When there is wide fluctuation in temperature, humidity or atmospheric
pressure.
• When the measuring pan or pan base is contaminated with powder or liquid,
erroneous weight values may result or indications may remain unstable.
Therefore, be sure to frequently clean the balance. When cleaning the balance,
be very careful not to allow dirt or liquid to penetrate inside (the mechanism
part).
• The windshield supplied with the round-pan type of balance is provided with
antistatic treatment. Wiping the windshield with a damp cloth may weaken the
antistatic effect. Therefore, use a dry cloth to clean the windshield. The
antistatic effect may be weakened over time. If this occurs, use a commercial
antistatic agent.
200006M01
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