The present invention relates to level detection and is particularly characterized by high precision, consistent with low cost, transducer apparatus.
The state of the art of a fluent material level measuring apparatus includes tapes which extend into a tank from the top and comprise a central conductor with insulating flanges at its edges around which are wrapped a spiral strip of nichrome wire or the like. A constant current source supplies current through the central strip with a return through the spiral and the portion of the tape below the liquid level is shorted out by pressing of the spiral against the central conductor. The state of the art also comprises optical sensors, other resistance and conductive probes and potentiometric floats and other means for detecting the change of liquid level within a liquid container. Such measurement apparatus is used in connection with monitoring wells, storage tanks for oil, and other industrial and agricultural liquids and the like.
It is an important object of the present invention to provide improvement in the precision of such instrumentation.
It is a further object of the invention to provide compactness of the elongated transducer element used in such apparatus consistent with the preceding object.
It is a further object of the invention to provide modularity of transducer elements to suit different measurement depths with a single, or limited number of, model(s), consistent with one or more of the preceding objects.
Further objects are to provide gauge pressure and/or hydraulic head measurement, sensitivity variation with localization of highest sensitivity in region of greatest need, commonality of apparatus to other force- or pressure-related parameter measurements, and/or modularity consistent with one or more of the preceding objects.
It is a further object of the invention to provide low cost consistent with one or more of the preceding objects.