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IPC Main Group
G01L 23/00

Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid

Introduced: September 1968

Last revised: January 2006

Classification Context

Section:
PHYSICS
Class:
MEASURING; TESTING
Subclass:
MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE

8 direct subcodes

Child Classifications

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  • G01L 23/02 mechanically indicating or recording and involving loaded or return springs
  • G01L 23/04 involving means subjected to known counteracting pressure
  • G01L 23/06 Indicating or recording by optical means
  • G01L 23/2 combined with planimeters or integrators
  • G01L 23/22 for detecting or indicating knocks in internal-combustion engines; Units comprising pressure-sensitive members combined with ignitors for firing internal-combustion engines
  • G01L 23/24 for measuring pressure in inlet or exhaust ducts of internal-combustion engines

Top Applicants

Top 10 applicants by patent filingsfor 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