It is a laboratory instrument used to measure small masses. The saucers with which it is measured are located in a transparent box, which has doors. This is in order that dust and air do not affect the measurements. It is used mainly in laboratories.
Thus, for their correct use, they are used on a rigid, level table, with a single entrance, with a minimum amount of sunlight. They can be digital or mechanical. It delivers very precise measurements, since they use an electronic system that works with hundredths. Its use is necessary in laboratories, for example, in the case of weighing ingredients for the manufacture of substances or medicines. In order for their operation to be correct, they must be calibrated before use. Its working range is a few grams and with a resolution of up to 0.1 µg.