Measuring and testing – Liquid level or depth gauge
Patent
1987-06-26
1990-04-03
Yasich, Daniel M.
Measuring and testing
Liquid level or depth gauge
141 95, 324675, 331 65, 340620, B65B 104, G01R 2726
Patent
active
049129767
ABSTRACT:
A liquid level sensing system comprising a probe and a reactive element carried by the probe. The reactive element forms a portion of a tuned circuit in a voltage-controlled oscillator. The output of the voltage-controlled oscillator is compared to a fixed frequency reference signal and a frequency/phase detector generates a signal indicative of any difference. The frequency/phase detector output is applied to the voltage-controlled oscillator to maintain the output frequency of the oscillator at the frequency of the reference signal. The output of the frequency/phase detector is also differentiated to develop a pulse when the frequency/phase detector output signal varies rapidly, indicating initial contact between the probe and the surface of a liquid held within a container.
REFERENCES:
patent: 2657579 (1953-11-01), Milson
patent: 2792566 (1957-05-01), Shanhouse et al.
patent: 3277711 (1966-10-01), Roberge
patent: 3321971 (1967-05-01), Llewellyn et al.
patent: 3596673 (1971-08-01), Laucourmet et al.
patent: 3635094 (1972-01-01), Oberli
patent: 3641544 (1972-02-01), Radin
patent: 3687632 (1972-09-01), Natelson
patent: 3694804 (1972-09-01), Hill
patent: 3793585 (1974-02-01), Wilska
patent: 3807231 (1974-04-01), Spaw
patent: 3821900 (1974-07-01), Preikschat
patent: 4099167 (1978-07-01), Pomerantz et al.
patent: 4165641 (1979-08-01), Pomerantz
patent: 4170135 (1979-10-01), Booman et al.
patent: 4182176 (1980-01-01), Playfoot et al.
patent: 4276258 (1981-06-01), Ginsberg et al.
patent: 4326851 (1982-04-01), Bello et al.
patent: 4389900 (1983-06-01), Gutierrez
patent: 4423628 (1984-01-01), Richter
patent: 4482891 (1984-11-01), Spencer
patent: 4495807 (1985-01-01), Field et al.
patent: 4502126 (1985-02-01), Mizoguchi
patent: 4543823 (1985-10-01), Nagy et al.
patent: 4615351 (1986-10-01), Schliefer et al.
patent: 4647854 (1987-03-01), Yamada et al.
patent: 4736638 (1988-04-01), Okawa et al.
European Patent Publication; No. 0101580-Berwind Corporation, published 02/29/84.
Beckman Instruments Inc.
Grant Arnold
Hampson Gary T.
May William H.
Yasich Daniel M.
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