Dropper
The normal dropper or dropper is a device for measuring / dosing small amounts of liquid in the form of drops .
It is mainly used in medicine , pharmacy and analysis . Drop counters are commonly used as inserts in medical jars and as pipettes that are integrated into the closure of medical jars. Dropper pipettes are also available as a stand-alone item, also as a single-use item.
The size, volume and mass of a drop depends on
- density
- viscosity
- Surface tension of the liquid
- Shape , type and dimensions of the dropper
- temperature
- Air pressure
The "normal dropper" of the European Pharmacopoeia is designed so that 20 drops of water at 20 ± 1 ° C result in a mass of 1,000 g ± 0.0050 g when the dropper is used vertically.
The basic rule is that the actual volume and mass of the drop depends largely on the liquid to be dropped. The manufacturer of the liquid provides exact information for a specific liquid or must be determined in each individual case.
The dosage of a liquid by means of drops is only of limited accuracy. Deviations of a few percent are always to be expected.
A special form of the drop counter is the drop stick (usually made of glass). The dropper is dipped into the liquid to be dripped and pulled out. A single drop forms, the volume and mass of which depends on the liquid as well as on the shape and diameter of the dropper stick and the speed with which the stick is pulled out of the liquid.
See also
Individual evidence
- ↑ European Pharmacopoeia , Deutscher Apotheker Verlag Stuttgart, 6th edition, 2008, p. 21, ISBN 978-3-7692-3962-1 .