G01K MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
Introduced: September 1968
Classification Context
- Section:
- PHYSICS
- Class:
- MEASURING; TESTING
- Subclass:
- MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
Description
G01K covers temperature measurement and heat quantity determination across diverse industrial and scientific applications. This subclass encompasses thermometers, pyrometers, calorimeters, and thermally-sensitive transducers that detect or quantify thermal phenomena. Included are resistance thermometers, thermocouples, radiation thermometers, and thermal sensors designed for process monitoring, temperature control, and heat transfer analysis. The subclass specifically addresses thermally-sensitive elements that do not fall under more specialized classifications, serving as a broad catch-all for temperature and heat measurement technologies not classified elsewhere in the IPC system.
Filing statistics
IPC subclass G01K recorded 118,108 patent applications worldwide between 2013 and 2023. Annual filings grew from 5,775 in 2013 to 14,309 in 2023 (+148%), peaking at 17,527 applications in 2020. The most active applicants in class G01 are SGCC(STATE GRID CORPORATION OF CHINA) (41,447 applications), CHINESE ACADEMY OF SCIENCES (32,952 applications) and ROBERT BOSCH (16,470 applications).
Source: EPO PATSTAT, worldwide filings
In class comparison
G01K ranks 10th of 18 subclasses with filings in G01, with 118,108 applications between 2013 and 2023, 2.5% of the class. Annual filings grew 148% from 2013 to 2023, above the class as a whole (+138%).
| Rank | Subclass | Title | Applications | Share |
|---|---|---|---|---|
| 1 | G01N, Investigating or Analysing Materials by Determining Their Chemical or Physical Properties | Investigating or Analysing Materials by Determining Their Chemical or Physical Properties | 1,640,918 | 34.9% |
| 2 | G01R, Measuring Electric Variables; Measuring Magnetic Variables | Measuring Electric Variables; Measuring Magnetic Variables | 598,083 | 12.7% |
| 3 | G01B, Measuring Length, Thickness or Similar Linear Dimensions; Measuring Angles; Measuring Areas; Measuring Irregularities of Surfaces or Contours | Measuring Length, Thickness or Similar Linear Dimensions; Measuring Angles; Measuring Areas; Measuring Irregularities of Surfaces or Contours | 395,662 | 8.4% |
| 4 | G01S, Radio Direction-Finding; Radio Navigation; Determining Distance or Velocity by Use of Radio Waves; Locating or Presence-Detecting by Use of the Reflection or Reradiation of Radio Waves; Analogous Arrangements Using Other Waves | Radio Direction-Finding; Radio Navigation; Determining Distance or Velocity by Use of Radio Waves; Locating or Presence-Detecting by Use of the Reflection or Reradiation of Radio Waves; Analogous Arrangements Using Other Waves | 358,214 | 7.6% |
| 5 | G01M, Testing Static or Dynamic Balance of Machines or Structures; Testing of Structures or Apparatus, Not Otherwise Provided for | Testing Static or Dynamic Balance of Machines or Structures; Testing of Structures or Apparatus, Not Otherwise Provided for | 339,843 | 7.2% |
| 6 | G01C, Measuring Distances, Levels or Bearings; Surveying; Navigation; Gyroscopic Instruments; Photogrammetry or Videogrammetry | Measuring Distances, Levels or Bearings; Surveying; Navigation; Gyroscopic Instruments; Photogrammetry or Videogrammetry | 271,474 | 5.8% |
| 7 | G01D, Measuring Not Specially Adapted for a Specific Variable; Arrangements for Measuring Two or More Variables Not Covered by a Single Other Subclass; Tariff Metering Apparatus; Transferring or Transducing Arrangements Not Specially Adapted for a Specific Variable; Measuring or Testing Not Otherwise Provided for | Measuring Not Specially Adapted for a Specific Variable; Arrangements for Measuring Two or More Variables Not Covered by a Single Other Subclass; Tariff Metering Apparatus; Transferring or Transducing Arrangements Not Specially Adapted for a Specific Variable; Measuring or Testing Not Otherwise Provided for | 207,395 | 4.4% |
| 8 | G01F, Measuring Volume, Volume Flow, Mass Flow, or Liquid Level; Metering by Volume | Measuring Volume, Volume Flow, Mass Flow, or Liquid Level; Metering by Volume | 157,084 | 3.3% |
| 9 | G01L, Measuring Force, Stress, Torque, Work, Mechanical Power, Mechanical Efficiency, or Fluid Pressure | Measuring Force, Stress, Torque, Work, Mechanical Power, Mechanical Efficiency, or Fluid Pressure | 145,069 | 3.1% |
| 10 | G01K | Measuring Temperature; Measuring Quantity of Heat; Thermally-Sensitive Elements Not Otherwise Provided for | 118,108 | 2.5% |
Source: EPO PATSTAT, worldwide filings
Additional Content
Glossary
thermometer thermometers includes thermally-sensitive elements not provided for in other subclasses.
Limiting references
Radiation pyrometry
Application references
Measuring temperature of human body parts for diagnostic purposes Heat-sensitive devices for control of fire-fighting equipment Heat-sensitive sheets for use in thermography Measuring temperature specially adapted to boreholes or wells Arrangements of temperature sensing elements for regulating or controlling in gas turbines Use of thermally-sensitive elements in systems controlling or regulating combustion Flow measurement by thermal means Investigating or analysing materials by use of thermal means, e.g. by calorimetry , Meteorology; Indication of human comfort ; Temperature control Fire alarms Thermally-sensitive members for thermally-actuated switches Temperature sensing in car batteries Control or measuring devices, e.g. for temperature of metal, in the art of manufacture of metal sheets, wires, rods, tubes or profiles Arrangement of indicating or measuring devices, e.g. for temperature or viscosity of the fused mass, in the art of casting of metals Measuring, controlling or regulating of temperature in injection moulding Indicating devices concerning coolant temperature, in the art of cooling of machines, engines, or internal-combustion engines Structural combination of nuclear reactor elements with sensitive instruments for measuring temperature
Related Keywords
10 direct subcodes
Child Classifications
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- G01K 1/00 Details of thermometers not specially adapted for particular types of thermometer
- G01K 11/00 Measuring temperature based on physical or chemical changes not covered by group , , , or
- G01K 13/00 Thermometers specially adapted for specific purposes
- G01K 15/00 Testing or calibrating of thermometers
- G01K 17/00 Measuring quantity of heat
- G01K 19/00 Testing or calibrating calorimeters
- G01K 3/00 Thermometers giving results other than momentary value of temperature
- G01K 5/00 Measuring temperature based on the expansion or contraction of a material
- G01K 7/00 Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat
- G01K 9/00 Measuring temperature based on movements caused by redistribution of weight, e.g. tilting thermometer
Top Applicants
Top 10 applicants by patent filingsfor class G01, 2013–2023, worldwide · Source: EPO PATSTAT
- SGCC(STATE GRID CORPORATION OF CHINA) 41,447
- CHINESE ACADEMY OF SCIENCES 32,952
- ROBERT BOSCH DE 16,470
- SAMSUNG ELECTRONICS COMPANY KR 10,052
- SINOPEC (CHINA PETROCHEMICAL CORPORATION) 9,573
- ZHEJIANG UNIVERSITY 9,529
- GUANGDONG POWER GRID CORPORATION 8,615
- TSINGHUA UNIVERSITY 7,805
- HALLIBURTON ENERGY SERVICES GROUP US 7,796
- QUALCOMM US 7,171