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CPC Subgroup
G01L 21/16

by measuring variation of frictional resistance of gases

Full Title

Vacuum gauges > by measuring variation of frictional resistance of gases

4 direct subcodes

Child Classifications

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  • G01L 21/18 using a pendulum
  • G01L 21/20 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. 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