This invention relates generally to an ultrasonic gas measuring device, for detecting and determining the concentration of a gas being measured, and incorporates means for providing a more effective and efficient determination of the concentration of any gas being detected whether said gas is in the process of being manufactured, or utilized, such as in medical, industrial, or other applications.
Various gas measuring means for determining the concentration of a gas within a particular specimen, such as the concentration of oxygen as used in medical applications, have been available in the art. For example, a Douglas Scientific Products, Inc. has been marketing an oxygen concentrator monitoring device, identified as the "Oxyalert," and which feeds a sample of the oxygen being measured into one area of a transducer assembly, and its sample chamber, and then at a remote location has an exit point for the measured gas, after passing it through an ultrasonic detector that senses the gas composition, and the concentration of specific gaseous components, within its device.
Hudson Oxygen Therapy Sales Co. markets an oxygen concentrator monitoring and regulation assembly, as shown in its U.S. Pat. No. 4,516,424, wherein the concentration of oxygen is detected by passing a gas over a fuel cell terminal that analyzes the gas being measured, by generating a signal as a result of exposure of the gas to the cell terminal, as a means for providing a determination of the concentration of the gas exposed thereto. Other patents to Hudson pertaining to the same technology are shown in the U.S. Pat. No. 4,627,860, U.S. Pat. No. 4,516,424, U.S. Pat. No. 4,561,287, and the U.S. Pat. No. 4,648,888.
The United States patent to Kniazuk, et al, U.S. Pat. No. 2,984,097, discloses a gas measuring apparatus, in which embodiment the development was used to determine the consumption of oxygen being made by a test specimen, and then measuring that degree of oxygen consumed by passing it through what is identified as a sonic generator.
The patent to Mechlenburg, U.S. Pat. No. 4,616,501, discloses a system that provides an indication of the concentration of at least one gas within a chamber, wherein a pair of operating frequencies generated from mechanical radiant energy are detected, their amplitudes measured, and then compared to a modeled amplitude response representative of a plurality of that gas's concentration to determine the specific concentration of the sample being tested.
The patent to Noguchi, et al, U.S. Pat. No. 4,662,212, defines a measuring instrument for concentration of gas, that does utilize and ultrasonic vibrator, but wherein the ultrasonic sensor is made humidity proof by utilizing various sealing materials on its outer surface by depositing a film formation by vacuum evaporation through the usage of select elements or compounds for achieving its structure. The device, though, is used for measuring the concentration of a gas passing through the instrument.
The U.K. published patent application No. GB2,087,559A, to Baird, et al, discloses a means for determining gas compositions accoustically, such as by an ultrasonic isolator, for determining and detecting the measurements of a fluid, which presumably includes gases, as well as liquids.
The patent No. SU112270A, of the Soviet Union, discloses a two/phase substance gas concentration acoustic measuring unit, for use for testing a substance, including a gaseous concentration. Phase-sensitive characteristics of the unit are determined during the change of the gas concentration, with the device being utilized upon a pipeline for measuring the gaseous substance and the concentration of that gas.
The patent to Ringwall, et al, U.S. Pat. No. 3,805,590, discloses an oxygen partial pressure sensor, which utilizes the detection of pressure for determining the amount of oxygen in a helium-oxygen gaseous mixture, and does define the usage of acoustic signal phase shifting to generate electrical signals by which the apparatus maintains oxygen partial pressure within required limits in its delivery of the gas apparently for breathing purposes at various water depths.
Other United States patents relating to detection of gas quantities include the United States patent to Advani, et al, U.S. Pat. No. 4,462,246; the United States patent to Terhune, U.S. Pat. No. 4,520,654; and, the United States patent to Ogura, et al, U.S. Pat. No. 4,581,942, relating to a measuring conduit for flow rate and concentration of fluid.
In addition to the foregoing, a company by the name of Ceramatec, Inc., of Salt Lake City, Utah, has a galvanic oxygen sensor device, which utilizes the fuel cell means for detection in determining the percentage of oxygen within a gaseous mixture.
The current invention, as distinct from the apparatuses and developments described in the prior art devices, provides for a more precise analysis of the concentration of a gas or gases within a gaseous mixture, primarily through the regulation of the gas to be measured as it passes into and through the sensing means, such as by achieving its laminar or divided flow, and through the incorporation of temperature, humidity, and pressure compensation means, furnishes a far more consistent and accurate analysis of the specific concentration of any one of the gases being detected, particularly oxygen, than can be achieved through the usage of the individual or combined prior art teachings.