watch glass
Học thuậtThân thiện
Definition
- Noun:
- A protective cover for a watch face: A transparent, often domed piece of glass or crystal that covers and protects the dial (face) of a wristwatch or pocket watch.
- A piece of laboratory glassware: A shallow, circular, flat-bottomed glass dish with a slight rim, used in scientific laboratories for tasks like evaporating small amounts of liquid, holding specimens, or covering beakers.
Examples of Usage
- Noun (Timepiece):
- He scratched the watch glass and needed to get it replaced.
- Sapphire crystal is a very hard material used for high-quality watch glasses.
- Noun (Laboratory):
- Place the sample on a watch glass to let the solvent evaporate.
- Cover the beaker with a watch glass to prevent splashes while allowing gases to escape.
Advanced Usage
- In horology (the study of timepieces), the watch glass is a critical component for both protection and legibility. Materials range from inexpensive acrylic to highly scratch-resistant synthetic sapphire.
- In laboratory procedures, a watch glass can be used as a surface for observing crystals under a microscope or for weighing small amounts of solid chemicals.
Variants and Related Words
- Crystal (n): A common synonym for the transparent cover on a watch face.
- Evaporating dish (n): A similar piece of lab equipment, often made of porcelain, used specifically for evaporation.
- Beaker (n): A cylindrical glass container used in labs, which a watch glass can cover.
Synonyms
- For timepiece: Crystal, watch crystal, lens.
- For laboratory: Glass dish, evaporating surface.
Related Phrases
- To have a cracked watch glass: A common phrase indicating damage to the protective cover of a watch.
- To evaporate on a watch glass: A standard laboratory instruction for concentrating a solution.
Noun
- a protective cover that protects the face of a watch
- laboratory glassware; a shallow glass dish used as an evaporating surface or to cover a beaker