Number | Name | Date | Kind |
---|---|---|---|
2772394 | Bradley | Nov 1956 | |
2885633 | Cook | May 1959 | |
2934699 | Offner | Apr 1960 | |
3043993 | Maltby | Jul 1962 | |
3086109 | Kaehms | Apr 1963 | |
3136952 | Hamby et al. | Jun 1964 | |
3375716 | Hersch | Apr 1968 | |
3543046 | Tiffany | Nov 1970 | |
3566259 | Wilson | Feb 1971 | |
3612997 | Paulkovich | Nov 1971 | |
3646541 | Rathbun | Feb 1972 | |
3694742 | Bergmanis et al. | Sep 1972 | |
3747407 | Wallman | Jul 1973 | |
3805156 | Norton et al. | Apr 1974 | |
3883800 | Dupont | May 1975 | |
4016490 | Weckenmann et al. | Apr 1977 | |
4099118 | Franklin et al. | Jul 1978 | |
4145619 | Tseng | Mar 1979 | |
4146834 | Maltby et al. | Mar 1979 | |
4347740 | Townsend | Jul 1982 | |
4642555 | Swartz et al. | Feb 1987 | |
4820268 | Kawamura et al. | Apr 1989 | |
4890491 | Vetter et al. | Jan 1990 | |
4898578 | Rubalcaba, Jr. | Feb 1990 | |
4976687 | Martin | Dec 1990 | |
4995268 | Ash et al. | Feb 1991 | |
5006997 | Reich | Apr 1991 | |
5078682 | Miki et al. | Jan 1992 |
Entry |
---|
Marsh, J. K., "Two Frequency Oscillator Detects Level of Liquid", Electronics, Mar. 20, 1967, p. 90. |