The handling, storage and cleaning of test weights used to check the balance are decisive factors for consistently correct weighing.
In order to be able to carry out accurate weighing in the long term you will receive tips here on how best to handle test weights.
These tips based on OIML R-111 are designed to help you avoid weighing errors and associated costs due to rework as well as recalls.
Storage of weights
Storage of weights near the balances to be tested
By storing the weights close to their environment of use comparable climate control of the balance and associated test weights can be ensured.
If it is not possible to store the weights near the place of use, make sure that the weights are acclimatized to the ambient conditions of the balance before use.
Since this - depending also on the size and accuracy class of the weight - always means an additional expenditure of time, we recommend that you store the weights near the balance.
Storage of the weights in their original packaging / in a suitable case
Ideally the weights are stored in their original packaging, i.e. in the plastic, wooden or aluminum weight case that matches the accuracy class.
These cases are precisely adapted to the weights, i.e. each weight has a fixed place and is protected from dust.
Larger weights can also be stored without a case with a cover, e.g. under a glass bell jar. It should be noted that the weight is not placed directly on the floor, but on a clean and acid-free paper towel.
Are you still looking for the right storage for your weight(s)? Then feel free to take a look at our webshop.
Cleaning of weights
Cleaning by user
Under ideal handling conditions cleaning is not usually necessary. However, if cleaning is necessary, lint-free microfiber cloths, rubber bellows or special brushes should be used for this purpose.
Please take care to keep the friction between the weight and the cloth as low as possible, otherwise electrostatic charges may occur, which in turn may influence the weighing values. It is recommended to let the weight rest for a while after cleaning.
Cleaning by KERN
If more intensive cleaning is necessary we recommend that you have it professionally performed in our laboratory.
In no case you should clean the weights themselves with abrasive or corrosive chemicals, as this may affect the conventional weighing value.
Handling of weights during use
When handling/lifting weights, it is essential to wear clean nylon or leather gloves (for high tolerance weights) or cotton gloves (for lower tolerance weights). The weights should not be touched with bare hands.
For smaller weights where it is not possible/meaningful to touch them with the hands due to their size and/or accuracy class tweezers with special coated tips (e.g. silicone or carbon) can be used. For larger weights special handles/weight forks can be used.
A visual inspection of the weights for impurities, corrosion, foreign matter, dust and fingerprints / finger grease should be carried out before each use. If necessary a magnifying glass or microscope can be used as an aid for this purpose.
If the weight is conspicuous in any of the above points we recommend that you do not use the weight and send it to our accredited calibration laboratory for calibration.
In case of any doubts about the accuracy of the weights we recommend not to use them.
Avoid pulling / pushing the weights on the metal weighing plate as this may cause minor abrasion damage and scratches.
It is generally recommended to have the weights recalibrated at regular intervals.