G01N 9/00 Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity
Introduced: September 1968
Last revised: January 2006
Classification Context
- Section:
- PHYSICS
- Class:
- MEASURING; TESTING
- Subclass:
- INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
Filing statistics
IPC G01N 9/00 belongs to the parent subclass G01N, which recorded 1,640,918 patent applications worldwide between 2013 and 2023. Annual filings grew from 83,705 in 2013 to 199,434 in 2023 (+138%). The most active applicants in class G01 are SGCC(STATE GRID CORPORATION OF CHINA) (41,447 applications), CHINESE ACADEMY OF SCIENCES (32,952 applications) and ROBERT BOSCH (16,470 applications).
Source: EPO PATSTAT, worldwide filings
Additional Content
density mass per unit volume specific gravity density of a substance divided by the density of water (since the latter is 1 gr/cm3, specific gravity is the same number as density but without any units)
Related Keywords
8 direct subcodes
Child Classifications
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- G01N 9/02 by measuring weight of a known volume
- G01N 9/08 by measuring buoyant force of solid materials by weighing both in air and in a liquid
- G01N 9/1 by observing bodies wholly or partially immersed in fluid materials
- G01N 9/24 by observing the transmission of wave or particle radiation through the material
- G01N 9/26 by measuring pressure differences
- G01N 9/3 by using centrifugal effects
- G01N 9/32 by using flow properties of fluids, e.g. flow through tubes or apertures
- G01N 9/36 Analysing materials by measuring the density or specific gravity, e.g. determining quantity of moisture
Top Applicants
Top 10 applicants by patent filingsfor class G01, 2013–2023, worldwide · Source: EPO PATSTAT
- SGCC(STATE GRID CORPORATION OF CHINA) 41,447
- CHINESE ACADEMY OF SCIENCES 32,952
- ROBERT BOSCH DE 16,470
- SAMSUNG ELECTRONICS COMPANY KR 10,052
- SINOPEC (CHINA PETROCHEMICAL CORPORATION) 9,573
- ZHEJIANG UNIVERSITY 9,529
- GUANGDONG POWER GRID CORPORATION 8,615
- TSINGHUA UNIVERSITY 7,805
- HALLIBURTON ENERGY SERVICES GROUP US 7,796
- QUALCOMM US 7,171