G01F 23/02
Indicating or measuring liquid level or level of fluent solid material: by
Official title: by gauge glasses or other apparatus involving a window or transparent tube for directly observing the level to be measured or the level of a liquid column in free communication with the main body of the liquid
G01F23/02 (Indicating or measuring liquid level or level of fluent solid material: by) appears on 354 US grants and 300 published applications in this corpus.
Search patents in G01F- Granted patents
- 354
- Published applications
- 300
- Assignees
- 240
- Inventors
- 734
- Latest grant
- 15 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 4 | 0 |
| 1977 | 3 | 0 |
| 1978 | 7 | 0 |
| 1979 | 2 | 0 |
| 1980 | 5 | 0 |
| 1981 | 4 | 0 |
| 1982 | 5 | 0 |
| 1983 | 5 | 0 |
| 1984 | 4 | 0 |
| 1985 | 5 | 0 |
| 1986 | 5 | 0 |
| 1987 | 5 | 0 |
| 1988 | 4 | 0 |
| 1989 | 11 | 0 |
| 1990 | 2 | 0 |
| 1991 | 7 | 0 |
| 1992 | 3 | 0 |
| 1993 | 9 | 0 |
| 1994 | 9 | 0 |
| 1995 | 7 | 0 |
| 1996 | 2 | 0 |
| 1997 | 10 | 0 |
| 1998 | 7 | 0 |
| 1999 | 3 | 0 |
| 2000 | 3 | 0 |
| 2001 | 5 | 1 |
| 2002 | 7 | 5 |
| 2003 | 4 | 7 |
| 2004 | 6 | 7 |
| 2005 | 7 | 10 |
| 2006 | 3 | 5 |
| 2007 | 5 | 9 |
| 2008 | 4 | 13 |
| 2009 | 6 | 7 |
| 2010 | 7 | 11 |
| 2011 | 1 | 9 |
| 2012 | 7 | 18 |
| 2013 | 8 | 7 |
| 2014 | 4 | 5 |
| 2015 | 9 | 13 |
| 2016 | 13 | 11 |
| 2017 | 11 | 17 |
| 2018 | 7 | 22 |
| 2019 | 20 | 20 |
| 2020 | 21 | 19 |
| 2021 | 14 | 15 |
| 2022 | 14 | 14 |
| 2023 | 10 | 14 |
| 2024 | 11 | 16 |
| 2025 | 9 | 15 |
| 2026 | 10 | 10 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Integral misalignment unions and interchangeable floating process connections for tubular gauge glass valves15 Sep 2026US 12,736,152 B1Kenco International, Inc.
- Machine fluid condition monitoring system7 Jul 2026US 12,674,697 B2Luneta, LLC
- Window with ferromagnetic marker for a measuring arrangement, and measuring arrangement with such a window9 Jun 2026US 12,650,371 B2Endress + Hauser GmbH + Co. KG
- Device for indicating a fluid level2 Jun 2026US 12,644,750 B2Hydac Accessories GmbH
- System and method for fuel monitoring and spill prevention19 May 2026US 12,631,479 B2BNSF Railway Company
- Hub cap with oil level indicator1 Oct 2026US 2026/0298692 A1Aperia Technologies, Inc.
- System and method for fuel monitoring and spill prevention17 Sep 2026US 2026/0276426 A1BNSF Railway Company
- Fluid level indicator for a hydraulic reservoir4 Jun 2026US 2026/0153103 A1Embraer S.A.
- Liquid level detection unit and liquid ejection device28 May 2026US 2026/0145435 A1Seiko Epson Corporation
- Device and method for measuring fluid flow and pressure under hyper-gravity environment21 May 2026US 2026/0139978 A1Zhejiang University
Most cited
By later US patents
- Fluid presence indicator for rotatable syringe120US 5,254,101 AMedrad, Inc. · 1993
- Capillary reservoir binary ink level sensor105US 5,079,570 AHewlett-Packard Company · 1992
- Liquid level indicator for humidifier78US 4,644,790 ASharp Kabushiki Kaisha · 1987
- Liquid collection system and related methods77US 8,172,817 B2Allegiance Corporation · 2012
- Sensor with electrical contact protection for use in fluid collection canister and negative pressure wound therapy systems including same68US 8,827,983 B2Smith & Nephew, Inc. · 2014