An important part of accurate weighing is regular balance calibration. If you perform a manual calibration using calibration weights, care needs to be taken to ensure their accuracy.
storage
Keep weights in their original packaging as much as possible, this avoids mixing up the weights and protects them from dust and other contamination. If the original box is not available, store the weights under a cover such as a bell jar on clean, acid-free tissue paper.
Weights should also be stored as close to the balance as possible to ensure they are all at the same temperature when in use. If the weights have been stored at different temperatures, they should be acclimatized to the same temperature as the balance before use.
processing method
Never handle calibration weights with bare hands. Oil and skin cells that may deposit on the weights can affect accuracy.
Use non-magnetic, non-abrasive tweezers or suitable cleaning leather, cotton or nylon gloves. For convenience, some calibration weight kits also come with gloves and tweezers.
After lifting the weight, handle it with care, taking care not to scratch or drag it on surfaces including the balance pan. Carefully place it on top of the pan and lift in the same way – scratching the pan can cause bruising.
examine
Before using the weight, inspect it for dust, water, and other contaminants, and if there is contamination on the weight , carefully clean it with a soft brush, microfiber cloth, or bellows to blow the dust off the surface. Never use cleaners or cleaners, as they will react with the surface and form oxides, adding weight.
Before using, also inspect each weight for damage, any fingerprints, marks, corrosion or other impurities can affect the accuracy of the weight. You might consider using a magnifying glass for a closer inspection.
If you need to dry or clean heavy items with a cloth or brush, let it sit to eliminate static charges.
Even with great care and handling, calibration weights should be recalibrated periodically to check that they are still within acceptable tolerances.
