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DIFF Main Group
G01N 9/00

Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity

Introduced: September 1968

Additional Content IPC

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)

Of 9 combined children, 8 exist in both systems.

1 codes are CPC-only extensions.

1 shared codes have differing titles between IPC and CPC.

Child Classifications

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  • G01N 9/08 by measuring buoyant force of solid materials by weighing both in air and in a liquid IPC+CPC Available in IPC and CPC
  • G01N 9/24 by observing the transmission of wave or particle radiation through the material IPC+CPC Available in IPC and CPC
  • G01N 9/30 by using centrifugal effects IPC+CPC Available in IPC and CPC
  • G01N 9/36 Analysing materials by measuring the density or specific gravity, e.g. determining quantity of moisture (methods of measurement in general G01N9/02 - G01N9/32) IPC+CPC Available in IPC and CPC

Top Applicants

Top Applicants (IPC)

Class G01,2013–2023, worldwide · Source: EPO PATSTAT

  1. SGCC(STATE GRID CORPORATION OF CHINA) 41,447
  2. CHINESE ACADEMY OF SCIENCES 32,952
  3. ROBERT BOSCH DE 16,470
  4. SAMSUNG ELECTRONICS COMPANY KR 10,052
  5. SINOPEC (CHINA PETROCHEMICAL CORPORATION) 9,573
  6. ZHEJIANG UNIVERSITY 9,529
  7. GUANGDONG POWER GRID CORPORATION 8,615
  8. TSINGHUA UNIVERSITY 7,805
  9. HALLIBURTON ENERGY SERVICES GROUP US 7,796
  10. QUALCOMM US 7,171

Top Applicants (CPC)

Class G01,2013–2023, worldwide · Source: EPO PATSTAT

  1. CHINESE ACADEMY OF SCIENCES 21,460
  2. ROBERT BOSCH DE 17,801
  3. SGCC(STATE GRID CORPORATION OF CHINA) 17,347
  4. SAMSUNG ELECTRONICS COMPANY KR 13,192
  5. QUALCOMM US 9,900
  6. HALLIBURTON ENERGY SERVICES GROUP US 9,742
  7. PHILIPS ELECTRONICS NL 7,249
  8. MITSUBISHI ELECTRIC CORPORATION JP 6,503
  9. ZHEJIANG UNIVERSITY 6,414
  10. DENSO CORPORATION JP 6,382