Watch Glasses
Watch Glasses
Watch glasses are shallow, circular, and concave, and may be used as beaker or flask covers, weighing, crystallization, and drying. Watch glasses are available in a variety of sizes and materials compatible with virtually all industrial chemicals and solvents. Some models are non-stick and some can withstand temperatures from cryogenic ranges up to 260°C.
Types of Watch Glasses
Watch glasses are normally made from glass (borosilicate glass or soda lime glass) or from plastics such as autoclavable polypropylene or chemical-resistant PTFE. The plastic versions are often single-use and disposable to prevent sample cross-contamination.
• Glass versions may be constructed using shatter-resistant compositions
• Glass versions often have polished, fused, or ground edges for cut-free, safe handling and durability
• Plastic versions may be used at low temperatures and are also lighter in weight
• All versions are available in a range of diameters, thicknesses, and capacities depending upon the intended application
What are Watch Glasses Used for?
• Holding biological samples or specimens for examination, either with the naked eye or under the microscope
• Demonstrations and displays, particularly in educational or classroom settings
• Observation of chemical processes such as precipitation or crystallization
• Weighing of powders, crystals, or liquids
• Gentle heating and/or evaporation of solids and liquids (borosilicate versions)
• Temporary covers for beakers, cylinders, and other containers to reduce evaporation and minimize ingress of dust and other airborne contamination (the curved surface helps prevent sliding and helps return of condensed liquid to the beaker)
DWK Life Sciences Watch Glass Dish, made from soda-lime glass, fused rim
The concave shape of the watch glass dish allow working in very small quantities (e.g. for pretreatments) and covering laboratory glassware with wide openings.
Pyrex™ Borosilicate Glass Watch Glasses
Manufactured from heat resistant Pyrex™ Borosilicate Glass. Pyrex™ Borosilicate Glass Watch Glasses are used for evaporation work and covering heated beakers. Fire-polished edges reduce chipping and breakage.
Scientific Glass Labs™ Soda Lime Glass Watch Glasses
Manufactured from Soda lime glass. Scientific Glass Labs™ Soda Lime Glass Watch Glasses with thin, clear glass and ground edge can be used to evaporate liquids, hold solids for weighing, or for heating small substances.
BRAND™ Watch Glass
Watch Glass constructed of soda-lime glass with ground edges.
BRAND™ PTFE Watch Glass
PTFE construction. Ideal for covering PTFE beakers.
BRAND™ PTFE Watch Glass
PTFE Watch Glasses are ideally suited for covering beakers.
DWK Life Sciences DURAN™ Watch Glass Dish, fused rim
The concave shape of the watch glass dish allow working in very small quantities (e.g. for pretreatments) and covering laboratory glassware with wide openings.
Bohlender™ PTFE Watch Dishes
Excellent for use in applications such as blends or covering vessels.
Kartell™ Polypropylene Watch Glasses
Use a watch glass to evaporate liquids, hold solids when weighing a sample, and in situations where cross-contamination could occur. Kartell™ Polypropylene Watch Glass has good heat and chemical resistance.
Kartell™ Plastilab™ Polypropylene Watch Glasses
Designed with moulded base for stability.
Karl Hecht™ Watch Glasses
These watch glasses are useful for evaporating liquids, holding solids, and heating small amounts of a sample.
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