초록 ▼

A dual-phase level monitoring (DPLM) instrument that provides continuous signals that enables determination of the location of the top surface of the lighter of two immiscible fluids (the product) and the hydrostatic pressure below the total fluid column of both immiscible fluids. By knowing the flu

A dual-phase level monitoring (DPLM) instrument that provides continuous signals that enables determination of the location of the top surface of the lighter of two immiscible fluids (the product) and the hydrostatic pressure below the total fluid column of both immiscible fluids. By knowing the fluid specific gravities, the output signals are processed to yield the location of the air/product and liquid/liquid interfaces, and the depth of the lighter phase. The instrument is intended for use in groundwater monitoring wells with a light non-aqueous phase liquid (product) and tanks or vessels with dual-phase liquids and level monitoring and/or control issues. The DPLM instrument includes a first pressure transducer situated beneath the surface of the liquid with a greater specific gravity, which will typically be ground water. A level element with a float selected so as to be buoyant and float on the surface of the lighter fluid is positioned above the first pressure transducer. A signal from the level element is proportional to the position of the float or the total distance the float is positioned above the bottom of the level element and therefore the total distance above the first pressure transducer, the pressure transducer located in the heaver liquid phase. A second pressure transducer can be deployed above the surface of the liquid if greater accuracy of measurement (as compared to assuming ambient pressure) is desired.

대표청구항 ▼

1. A method of monitoring dual-phase liquid and interface levels comprising the following steps:a) removably suspending a monitoring instrument in a site to be monitored,b) providing a level element that floats on an upper surface of a product layer of liquid in said site,c) providing a first pressu

1. A method of monitoring dual-phase liquid and interface levels comprising the following steps:a) removably suspending a monitoring instrument in a site to be monitored,b) providing a level element that floats on an upper surface of a product layer of liquid in said site,c) providing a first pressure transducer that is connected to said level element at a fixed distance below said level element, said distance being such that said first pressure transducer is suspended in a heavier one of the two liquids being monitored,d) continuously monitoring output signals from said first pressure transducer indicating measured fluid pressure,e) continuously monitoring output signals from said level element indicating measured fluid pressure, andf) comparing said output signals of said first pressure transducer and said level element to a reference pressure to calculate a level of a groundwater and product interface and a thickness of said product layer.2. The method as defined in claim 1 wherein:said reference pressure is assumed to be a known pressure.3. The method as defined in claim 1 wherein:said reference pressure is measured at a reference side of said first pressure transducer, an airway being provided between said first pressure transducer and a position above said upper surface of said product layer.4. The method as defined in claim 1 wherein:said first pressure transducer is in communication with a power supply, processing, and display unit.5. The method as defined in claim 1 wherein:said level element comprises a float with a guide tube, a magnet movable along a length of said guide tube, and a reed-switch installed in a travel path of said magnet; such that said magnet moves along said guide tube in response to a changing fluid level, thereby triggering different levels of resistance in said reed-switch and varying said output signal of said level element.6. The method as defined in claim 1 wherein:said reference pressure is measured by a second pressure transducer positioned above said upper surface of said product layer.7. The method as defined in claim 6 wherein:said second pressure transducer is in communication with a power supply, processing, and display unit.