specific gravity: meaning, definition, pronunciation and examples
LowTechnical, Scientific
Quick answer
What does “specific gravity” mean?
The ratio of the density of a substance to the density of a standard reference substance, usually water for liquids and solids, and air for gases.
Audio
Pronunciation
Definition
Meaning and Definition
The ratio of the density of a substance to the density of a standard reference substance, usually water for liquids and solids, and air for gases.
A dimensionless value representing the relative heaviness or density of a material compared to a standard; commonly used in physics, chemistry, geology, and engineering to characterize materials and assess purity or composition.
Dialectal Variation
British vs American Usage
Differences
No significant difference in meaning or usage. Both use the same term. In highly technical writing, 'relative density' might be slightly preferred as the more internationally standard term.
Connotations
Identical scientific connotations in both varieties.
Frequency
Equally low-frequency and specialized in both regions, confined to scientific, industrial, and educational contexts.
Grammar
How to Use “specific gravity” in a Sentence
The specific gravity of [SUBSTANCE] is [VALUE].To measure/find the specific gravity of [SUBSTANCE].[SUBSTANCE] has a specific gravity of [VALUE].Vocabulary
Collocations
Examples
Examples of “specific gravity” in a Sentence
adjective
British English
- The specific-gravity reading was crucial for the experiment.
American English
- They used a specific-gravity hydrometer to test the coolant.
Usage
Meaning in Context
Business
Rare, except in specific industries like brewing, metallurgy, or battery manufacturing for quality control.
Academic
Common in physics, chemistry, materials science, geology, and engineering textbooks and labs.
Everyday
Virtually never used. A layperson would say 'how dense/heavy it is compared to water'.
Technical
The primary register. Used in lab reports, material data sheets, industrial specifications, and scientific papers.
Vocabulary
Synonyms of “specific gravity”
Neutral
Weak
Vocabulary
Antonyms of “specific gravity”
Watch out
Common Mistakes When Using “specific gravity”
- Adding units (e.g., 'specific gravity of 1.2 g/cm³' – incorrect, it's just 1.2).
- Confusing it with 'density' without the comparative aspect.
- Using it for abstract, non-physical concepts (e.g., 'the specific gravity of the argument').
FAQ
Frequently Asked Questions
No. Density is mass per unit volume (e.g., g/cm³). Specific gravity is a ratio comparing a substance's density to the density of water (for liquids/solids). It has no units.
Water is abundant, well-understood, and has a convenient density of approximately 1 g/cm³ at 4°C, making calculations and mental comparisons simple (e.g., SG of 2.5 means 2.5 times denser than water).
Yes, but the standard reference is usually dry air at standard temperature and pressure, not water.
Common tools include a hydrometer (for liquids), a pycnometer (for precise solid or liquid measurements), or by calculating it from separately measured mass and volume.
The ratio of the density of a substance to the density of a standard reference substance, usually water for liquids and solids, and air for gases.
Specific gravity is usually technical, scientific in register.
Specific gravity: in British English it is pronounced /spəˌsɪf.ɪk ˈɡræv.ə.ti/, and in American English it is pronounced /spəˌsɪf.ɪk ˈɡræv.ə.t̬i/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
Think SPECIFICally about GRAVITY (weight): it's the SPECIFIC (particular) measure of an object's GRAVITY (heaviness) compared to water's.
Conceptual Metaphor
HEAVINESS IS A RATIO (abstracting the property of weight/density into a pure, comparable number).
Practice
Quiz
What does a specific gravity of less than 1.0 indicate?