Process and apparatus for detecting the limit level of liquids a

Details Process and apparatus for detecting the limit level of liquids a Process and apparatus for detecting the limit level of liquids a

1996-08-14

1999-11-02

Walton, George L.

Fluid handling

Processes

With control of flow by a condition or characteristic of a...

73290V, 137392, 310332, F16K 3102, H01L 4108

Patent

active

059751029

ABSTRACT:
In a process for the detection of the limit level of liquids and bulk materials in containers and pipelines, the change in the oscillation behavior of a sensor which is excited to oscillation is detected electronically and used to trigger a switch command. As sensor there is used a parallel bimorph piezoelectric element (22) having a common central electrode (44) and two outer electrodes (46, 48). A first alternating voltage (U1) with an oscillator frequency (f1) is applied between the central electrode (44) and a first outer electrode (46), a second alternating voltage is measured as amplitude of oscillation (U2) with corresponding oscillation frequency (f2) between the central electrode (44) and the second outer electrode (48), and the measured amplitude of oscillation (U2) or oscillation frequency (f2) is converted into an output switch signal.
In a device suitable for the carrying out of the process, the piezoelectric element (22) is inserted in liquid-tight manner into a plastic cover (24), the plastic cover (24) in its turn being fastened in liquid-tight manner to a plastic housing which passes through the wall (16) of a container or a pipeline, and the plastic cover (24) together with the piezoelectric element (22) extends into a protective tube (18) developed on the plastic housing (12).

REFERENCES:
patent: 2478223 (1949-08-01), Argabrite
patent: 3625058 (1971-12-01), Endress et al.
patent: 3949247 (1976-04-01), Fenner et al.
patent: 4112279 (1978-09-01), Brohard
patent: 4325416 (1982-04-01), Hermann
patent: 4383443 (1983-05-01), Langdon
patent: 4553061 (1985-11-01), Germano
patent: 4594584 (1986-06-01), Pfeiffer et al.
patent: 4785663 (1988-11-01), Hermann
patent: 4833920 (1989-05-01), Knecht et al.
patent: 4884090 (1989-11-01), Tanaka et al.
patent: 4896535 (1990-01-01), Duckart et al.
patent: 4896536 (1990-01-01), Benz
patent: 5068567 (1991-11-01), Jones
patent: 5076314 (1991-12-01), Ikehata et al.
patent: 5083056 (1992-01-01), Kondou
patent: 5191316 (1993-03-01), Dreyer
patent: 5382864 (1995-01-01), Morikawa et al.
patent: 5625343 (1997-04-01), Rottmar
patent: 5631633 (1997-05-01), Dreyer et al.
R. M. Langdon, Ph.D., "Vibratory Process Control Transducers", Marconi Review, vol. 43, No. 218, 3rd Quarter (1980), pp. 156-175.

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