Balances are expensive and chemicals spilled on the balance may corrode the delicate mechanism, causing readings to be incorrect or preventing the balance from working at all. Therefore, several rules for keeping a balance (and the balance area) clean are described below.
1. Never weigh a sample directly on the balance pan.
2. Never add chemicals to a weighing vessel while the vessel is on the pan.
3. Before leaving the balance, clean up the area. Use a brush to clean all solids from the balance pan, and wipe up any liquids. Wear gloves while cleaning if a material may be hazardous. Also clean the area around the balance. Dispose of any excess or unused chemicals in an appropriate waste container.