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DIFF Subgroup
G01N 21/80

Indicating pH value

Introduced: January 1980

Full Title

Full titles differ between systems:

IPC:

Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light > Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated > by observing the effect on a chemical indicator > producing a change of colour > Indicating pH value

CPC:

Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light (G01N3/00 - G01N19/00 take precedence) > Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated (systems in which material is burnt in a flame or plasma G01N21/72, G01N21/73) > by observing the effect on a chemical indicator > producing a change of colour > Indicating pH value

No child classifications to compare. This is a leaf node in both 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