No matter what type of analytical balance is employed, due attention must be paid to the manner in which it is used. The following remarks apply particularly to electronic balances.
1. Never exceed the stated maximum load of the balance.
2. The balance must be kept clean/ Remove dust from the pan and from the floor of the pan compartment with a hairbrush.
3. Object to be weighed should never b handled with the fingers; always use tongs or a loop of clean paper.
4. Objects to be weighed should be allowed to attain the temperature of the balance before weighing, and if the object has been heated, sufficient time must be allowed for cooling. The time required to attain the temperature of the balance varies with the size, etc., of the object, but as a rule, 30-40 minutes is sufficient.
5. No chemicals or objects which might injure the balance pan should ever be placed directly on it. Substances must be weighed in suitable containers, such as small beakers, weighing bottles, or upon watch glasses. Liquids and volatile or hygroscopic solids must be weighed in tightly closed vessels, such as stoppered weighing bottles.
6. Nothing must be left on the pan when the weighing has been completed. If any substance is spilled accidentally upon the pan or upon the floor of the balance compartment, it must be removed at once.
7. Exposure of the balance to corrosive atmospheres must be avoided.
The actual weighting process will include the following steps.
1. Brust the balance pan lightly with a hairbrush to remove any dust.
2. With the balance at rest, place the object to be weighed, which must be at or close to room temperature, on the pan, and close the pan compartment case.
3. Set the ON/OFF control of the balance to the 'ON' position and record the weight shown on the digital display; if the balance is linked to a printer, confirm that the printed result agrees with the digital display. Return the control to the 'OFF' position after using it.
4. When all weighings have been completed, remove the object which has been weighed, clear up any accidental spullages, and close the pan compartment.
