Watch glass

As a watch glass watch glass or curved windows of transparent material are designated with a diameter of six to 20 centimeters in the chemical laboratory technology.

Due to the concave shape can be divided into watch-glasses small amounts of liquids fill, to evaporate them. Watch glasses made ​​of borosilicate glass can be heated via Bunsen burners, in order to accelerate the evaporation.

Watch glasses are often used to cover beakers, petri dishes, or the opening of the piston or cylinder to protect against contamination and increased spatter evaporation for a short time. In the laboratory, covering containers instead of with watch glasses complete closure today is often done with parafilm or aluminum foil as a sealing film, often with plugs.

Further, the watch glasses suitable for small amounts of substances and a weigh or dry in a drying cabinet.