Definition

1. Noun:
   • Hydrometer: "phù kế" is a scientific instrument used to measure the specific gravity or relative density of liquids. It typically consists of a sealed glass tube with a weighted bulb at one end and a calibrated stem.

Usage Examples

• Noun:
  • Nhà hóa học sử dụng phù kế để đo nồng độ dung dịch. (The chemist uses a hydrometer to measure the concentration of the solution.)
  • Phù kế là một dụng cụ quan trọng trong phòng thí nghiệm. (A hydrometer is an important instrument in the laboratory.)

Advanced Usage

• Technical Context: In physics and chemistry, "phù kế" is used for precise measurements, such as determining the alcohol content in spirits, the salinity of water, or the state of charge in a car battery's electrolyte.
  • Kiểm tra axit trong ắc quy bằng phù kế. (Check the battery acid with a hydrometer.)

Variants and Related Words

• Tỷ trọng kế: Another term for hydrometer, literally "specific gravity meter."
• Areometer: The English synonym derived from French/Greek, sometimes used in technical contexts.

Synonyms

• Density meter: A more general term for instruments measuring density.
• Gravimeter: While often used for measuring gravity, in some contexts it can refer to density measurement devices for liquids.

Related Phrases (Technical Terms)

• Đo tỷ trọng: To measure specific gravity.
  • Công việc này yêu cầu phải đo tỷ trọng chính xác. (This task requires precise measurement of specific gravity.)
• Thả phù kế: To float/immerse the hydrometer.
  • Nhẹ nhàng thả phù kế vào chất lỏng cần đo. (Gently lower the hydrometer into the liquid to be measured.)

1. (vật lý) Areometer