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IPC Subgroup
G01L 21/16

by measuring variation of frictional resistance of gases

Introduced: September 1968

Last revised: January 2006

Full Title

Vacuum gauges > by measuring variation of frictional resistance of gases

Classification Context

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

4 direct subcodes

Child Classifications

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  • G01L 21/18 using a pendulum
  • G01L 21/2 using members oscillating about a vertical axis
  • G01L 21/22 using resonance effects of a vibrating body; Vacuum gauges of the Klumb type
  • G01L 21/24 using rotating members; Vacuum gauges of the Langmuir type

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