A&D AD-4212A-100/200/600/1000 Postal Equipment User Manual


 
12
When an operator is static charged
If an operator’s clothes are static charged, especially in winter, it may be a cause for
unstable weight values.
Wear an anti-static wrist strap.
Errors due to air flow
Where the influence of ambient air flow is great
such as: close to an air conditioner, door or
passage way. Even very subtle air flow that is
hard to be detected may influence the weighing
operation.
Avoid those areas as a weighing site.
If weighing is to be performed in such an
area, use a breeze break or take other
appropriate measures.
Where the influence of heat or drafts is great
Eliminate temperature differences between
a sample and the environment.
When a sample is warmer (cooler) than the
ambient temperature, the sample will be
lighter (heavier) than the true weight. This
error is due to a rising (falling) draft around
the sample.
Do not touch the sample directly with your
hand. Use tweezers or other tools.
If you touch the sample, the same type
error described above will occur.
Do not perform weighing where it is exposed to direct sunlight. Weighing errors may
occur due to sudden temperature change or drafts.
Where the influence of vibration is great, such as:
(1) Soft ground (2) Second or higher floor (3) Near center of a floor far from pillars (4) Seismic
isolated structures (5) Near tall buildings.
In the areas listed above, the scale may yield unstable weight values on windy days or after an
earthquake. Especially in case of (4) and (5), weight values may be unstable during and for a
long period of time after strong winds or an earthquake.
Errors due to other causes
Change in temperature or humidity
A sudden change in temperature or humidity can generate a draft and cause the balance to
absorb or exude moisture, which leads to weighing errors.
Avoid sudden change in temperature or humidity.
Use an air conditioner to control the temperature or humidity.
40 C
20 C
Draft
Influence of the air flow
makes the weight
value unstable