G01R 27/22
Measuring resistance of fluids
G01R27/22 (Measuring resistance of fluids) appears on 232 US grants and 141 published applications in this corpus.
Search patents in G01R- Granted patents
- 232
- Published applications
- 141
- Assignees
- 181
- Inventors
- 427
- Latest grant
- 25 Aug 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 13 | 0 |
| 1977 | 10 | 0 |
| 1978 | 10 | 0 |
| 1979 | 4 | 0 |
| 1980 | 3 | 0 |
| 1981 | 7 | 0 |
| 1982 | 5 | 0 |
| 1983 | 0 | 0 |
| 1984 | 1 | 0 |
| 1985 | 6 | 0 |
| 1986 | 0 | 0 |
| 1987 | 3 | 0 |
| 1988 | 3 | 0 |
| 1989 | 8 | 0 |
| 1990 | 4 | 0 |
| 1991 | 7 | 0 |
| 1992 | 3 | 0 |
| 1993 | 5 | 0 |
| 1994 | 6 | 0 |
| 1995 | 1 | 0 |
| 1996 | 5 | 0 |
| 1997 | 1 | 0 |
| 1998 | 2 | 0 |
| 1999 | 3 | 0 |
| 2000 | 0 | 0 |
| 2001 | 2 | 0 |
| 2002 | 3 | 2 |
| 2003 | 2 | 0 |
| 2004 | 0 | 0 |
| 2005 | 1 | 4 |
| 2006 | 3 | 2 |
| 2007 | 1 | 2 |
| 2008 | 2 | 4 |
| 2009 | 4 | 4 |
| 2010 | 2 | 1 |
| 2011 | 0 | 3 |
| 2012 | 1 | 3 |
| 2013 | 6 | 6 |
| 2014 | 0 | 4 |
| 2015 | 8 | 4 |
| 2016 | 6 | 5 |
| 2017 | 4 | 8 |
| 2018 | 6 | 13 |
| 2019 | 8 | 10 |
| 2020 | 10 | 13 |
| 2021 | 8 | 7 |
| 2022 | 8 | 9 |
| 2023 | 15 | 14 |
| 2024 | 8 | 7 |
| 2025 | 10 | 8 |
| 2026 | 4 | 8 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Method of measuring a conductivity of a liquid using a conductivity sensor25 Aug 2026US 12,716,857 B2NGK Insulators, Ltd.
- Circuit for impedance measurements26 May 2026US 12,638,487 B2Mettler-Toledo AG
- Sensor device for monitoring the dielectric strength of a dielectric fluid, in particular a fluid for the thermal conditioning of a battery5 May 2026US 12,618,891 B2ELTEK S.p.A.
- Impurity detection support device and impurity detection support method10 Feb 2026US 12,546,735 B2Panasonic Intellectual Property Management Co., Ltd.
- Inductive conductivity sensor circuit, inductive conductivity sensor and method of operating the circuit16 Dec 2025US 12,498,439 B2Endress+Hauser Conducta GmbH+Co. KG
- Fluid leakage detection3 Sep 2026US 2026/0259100 A1Aivres Systems Inc.
- Current density measuring apparatus and corrosion measuring method27 Aug 2026US 2026/0251552 A1National Institute of Maritime, Port and Aviation Technology
- Conductivity/resistivity cell, water purification system, and method of determining the conductivity and/or resistivity of a sample liquid30 Jul 2026US 2026/0219221 A1Merck Patent GmbH
- Measurement circuitry23 Apr 2026US 2026/0108185 A1Cirrus Logic International Semiconductor Ltd.
- Capacitive electrical conductivity sensor integrated in a water meter23 Apr 2026US 2026/0110562 A1Itron, Inc.
Most cited
By later US patents
- Liquid conductivity measuring system and sample cards therefor394US 4,301,412 AUnited States Surgical Corporation · 1981
- Electrical liquid conductivity measuring system147US 4,303,887 AUnited States Surgical Corporation · 1981
- Disposable sample card and method of making same101US 4,301,414 AUnited States Surgical Corporation · 1981
- Fluid conductivity measurement79US 4,138,639 A1979
- Three-toroid electrodeless conductivity cell72US 5,157,332 AThe Foxboro Company · 1992