Communications: electrical – Condition responsive indicating system – Specific condition
Patent
1990-12-21
1991-10-22
Crosland, Donnie L.
Communications: electrical
Condition responsive indicating system
Specific condition
340618, 73302, G08B 2100
Patent
active
050599542
ABSTRACT:
A sensing system for detecting a low level of liquid in a container employs an open-ended probe which is partially submerged in the liquid. The probe contains a pressurized compressible fluid, typically air, the pressure of which is related to the level of the liquid in the container, being a function of the static head of the liquid. A pressure switch fluidly connected to the probe is actuated when the pressure in the probe falls below a predetermined level. The pressure switch activates an air pump, which pumps compressed air into the probe to try and restore the predetermined pressure level, and the switch simultaneously actuates a time delay unit, which in turn initiates a time delay period. If pressure in the probe is restored to the predetermined level prior to the expiration of the time delay period, the time delay unit is reset and the air pump is shut off, since restoration of the pressure indicates that the liquid level is not really low, the low pressure condition is caused by a leak or absorption. However, if the pressure in the probe is not restored to the predetermined level when the time delay period expires, an alarm indicating low liquid level in the container is actuated, so that the level may be replenished.
REFERENCES:
patent: 2003759 (1931-12-01), Reichel
patent: 2640977 (1953-06-01), Parisi
patent: 3230769 (1962-06-01), Carver et al.
patent: 3587316 (1971-06-01), Kapteyn
patent: 3834236 (1974-09-01), Durin
patent: 4002068 (1977-01-01), Borst
patent: 4199983 (1980-04-01), Kobayashi et al.
patent: 4204203 (1980-05-01), Verne
patent: 4480610 (1984-11-01), Stinson
patent: 4639738 (1987-01-01), Young et al.
Beldham Paul M.
Bremer Larry G.
Jones Erik W.
Crosland Donnie L.
Hofsass Jeffery A.
Knight Equipment Corp.
Peterson Gordon L.
LandOfFree
Liquid level sensing system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Liquid level sensing system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Liquid level sensing system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-111359