refractometer
/ˌriːfrækˈtɑːmɪtər/
noun
- An instrument used to measure the refractive index of a substance, often to determine its concentration or purity.
- The winemaker used a refractometer to check the sugar level in the grape juice.
- A simple refractometer can help aquarium owners measure the saltiness of the water.
- In the lab, the technician cleaned the refractometer before testing the new chemical sample.