Description

Best Location for an Analytical Balance
These sensitive devices are easily affected by air currents, temperature and other physical variables, so they are enclosed or shielded to reduce exposure. Still, the enclosures will not be able to protect them completely.

You need to ensure they’re placed in a secure location that is quiet, clean, temperature-controlled and draft-free.
If the building floor isn’t level, the analytical scale should be placed near an outside wall to reduce misalignment issues.
They should be placed on a sturdy and level weighing table, with a cork or rubber layer to absorb vibrations.
For higher accuracy and readability, use a balance with a self-correct feature or additional filters against physical influences.

Physical Influences and Calibration

Analytical balance readouts can be affected by changes in the sample and/or container as well as other physical influences.

Use clean and dry containers for samples, and avoid beakers with large or wide openings. Pick the smallest container possible, and cover it if needed.
Condition the sample/container to the prevailing temperature, to avoid issues with repeatability and weighing results. You may also find drifts in the readout value (even with a stable display when the balance isn’t loaded) otherwise.
Evaporation may occur in uncovered samples/containers, or they may absorb water if handled with bare fingers. Readouts could increase or decrease continuously, or you may find drift (even with a stable display when the balance isn’t loaded).
Electrostatically charged samples/containers (e.g. glass or plastic) or very low humidity may cause non-repeatable values or drifts in one direction. Shield the sample with metal foil or a metal container, increase the humidity and neutralize static electricity with an ionizing blower.
Magnetic force fields can lead to stable but non-repeatable values, or changes in display based on the sample’s position. Avoid using magnetic stirring bars, shield samples with Mumetal foil or non-magnetic objects, use anti-magnetic weighing pans and demagnetize the pan before weighing.

To maintain analytical balance accuracy, it’s important to calibrate it on a regular basis.

If your balance offers an internal calibration feature that requires minimal user input, follow the manufacturer’s instructions and use this feature regularly. However, if quantitative chemical analysis plays a critical role in your industry (e.g. food or pharma), conduct your own tests as well.
t’s a good idea to set up a regular calibration schedule, so your balances can be tested for accuracy every few months. Also, make sure to recalibrate them in case of any environmental changes (e.g. relocating the device).
The appropriate calibration settings for a certain environment can be determined with certified calibration masses, which is especially crucial when you’re calibrating sensitive instruments like analytical balances.