| # | Country | Total Patents | |
|---|---|---|---|
| #1 | United States | 9 | |
| #2 | Canada | 4 | |
| #3 | Germany | 3 | |
| #4 | EPO (European Patent Office) | 2 | |
| #5 | United Kingdom | 2 | |
| #6 | WIPO (World Intellectual Property Organization) | 2 | |
| #7 | Australia | 1 | |
| #8 | Sweden | 1 | |
| #9 | USSR (Union of Socialist Soviet Republics) | 1 |
| # | Industry | |
|---|---|---|
| #1 | Measurement | |
| #2 | Electrical machinery and energy | |
| #3 | Control | |
| #4 | Packaging and shipping |
| # | Technology | |
|---|---|---|
| #1 | Measuring volume | |
| #2 | Measuring length, angles and areas | |
| #3 | Control or regulating systems | |
| #4 | Elevators and escalators | |
| #5 | Special measuring | |
| #6 | Electric motor controls | |
| #7 | Resistors | |
| #8 | Measuring temperature |
| # | Name | Total Patents |
|---|---|---|
| #1 | Ehrenfried Albert D | 14 |
| #2 | Pierce Norton T | 7 |
| #3 | Gunnarson John A | 6 |
| #4 | Pierce William E | 6 |
| #5 | Halstead Floyd E | 3 |
| #6 | Pierce N | 3 |
| #7 | Ehrenfried A | 3 |
| #8 | Thorstensen Thomas C | 3 |
| #9 | Niejadlik John | 3 |
| #10 | Dews Edwin P | 3 |
| Publication | Filing date | Title |
|---|---|---|
| US4967594A | Sheathing and venting of resistance-tape level sensor | |
| US4942764A | Mounting head for a resistance-tape level sensor | |
| US4816799A | Resistive material level sensor | |
| US4231025A | Level and temperature readout and alarm system | |
| US3792407A | Channel mounted level sensor | |
| CA927948A | Dry bulk level sensing system | |
| US3783689A | Discrete level detector | |
| US3663881A | Continuous position sensing system | |
| US3583221A | Dry bulk level sensing system | |
| US3511090A | Fluent material level sensor | |
| CA909907A | Fluent material level sensor |