The present invention is a liquid depth sensing system utilizing the bubble tube or purge operating principle. The invention utilizes a pneumatic pump motor (28) as a regulating device, by operating the motor (28) only as required to produce sufficient pressure for measuring the liquid depth. The present system may be applied to either open or closed liquid containers (10), and may be adapted for use in the bottling industry to provide extreme accuracy and rapid shutoff during filing operations.

Liquid depth sensing system

Each unit of an array of submerged oceanographic devices is provided with a depth gauge of the air bubbler type. A typical depth gauge consists of a tube or air line that has one end fluidly coupled to a manifold; the other end of the air line is open. The open end of the air line is secured adjacent a corresponding submerged device. A small flow of air is established from the manifold, through the air line, to bubble out the open end into the water. A pressure transducer is fluidly coupled to the air line and senses the backpressure due to the hydrostatic water head existing above the submerged device. Means are provided for inhibiting pneumatic cross feed in the manifold between the respective air lines.

Multiple-unit water depth sensor system

A system and method for providing for a remote readout of liquid levels in an oil tank, which system includes an oil tank having an air vent and containing liquid amounts whose levels are to be determined; a single bubble tube inserted in the oil tank, with one end adjacent the bottom surface of the oil tank; an integral source of compressed air for supply to the single bubble tube; a pressure sensor and a timer actuated on demand or periodically at a fixed time, to actuate the integral air compressor for a short defined time period, and immediately thereafter to actuate the pressure sensor, to sense the amount or level of the oil in the oil tank; manual or telephone actuation of the timer, when determination of the amount or level of the oil in the oil tank is desired; and a computer-memory and display means at a remote location, to receive and display to the user the information on the amount or level of oil in the oil tank.

Fuel oil monitor system and method

A pipe probe is installed downward into the liquid contained in the tank and is connected pneumatically to a remote reporting unit located in the operator's area. An air pump pressurizes the probe, increasing the pressure up to the point at which the liquid is completely displaced from the probe and bubbles of air evolve from the end of the probe. At that point the pressure is proportional to the height of the liquid in the tank. A pneumatic connection from the probe to the reporting unit refers the pressure to a piezoresistive pressure transducer working in concert with an electronic process controller. The controller produces a voltage output which is reported as a digital numeric readout, reading in volts or in programmed engineering units. Jittery variations in the least significant figure of the numeric readout, which are associated with the evolution of air bubbles from the end of the probe, are eliminated by adding an air tank buffer to the pneumatic system.

Asphalt oil tank monitor

A liquid level monitoring system, which monitors the level of liquid in a storage tank, includes a differential pressure sensor that uses a magnetic fluid, or ferrofluid, sensing element. The pressure sensor is U-shaped with a first one leg connected, via a first pressure chamber, to a bubbler tube that extends downwardly into the storage tank. The second leg of the U-shaped sensor connects to a second pressure chamber, which applies to the second leg a selected, fixed pressure. The pressure applied to the first leg of the sensor is proportional to the hydrostatic back pressure in the bubbler tube, which varies directly with the level of liquid in the storage tank. Wound around the legs of the pressure sensor are inductance coils. The inductances of these coils change as the ferrofluid sensing element moves within the sensor. Accordingly, the inductances change as the level of liquid in the storage tank varies. The inductor coils are connected to a control system which produces a control signal based on the differences of the inductances. This control signal thus varies essentially continuously with changes in the level of liquid in the storage tank. The control signal is preferably used to control a storage tank control system which includes various pumps. In response to the control signal, the pumps force liquid into or out of the storage tank, as appropriate. Alternatively, an array of sensing elements may be used to determine the position of the ferrofluid. Signals from the various sensing elements in the array are essentially encoded to produce an output signal that corresponds to the level of fluid in the storage tank.

Sholokhov Vitalij G

Papers

Hydrostatic level gauge

Hydrostatic level indicator

Device for measuring level of liquid