Atwood Industries, Inc.

Dura Global Technologies, Inc.

Halitec Industries Corp.

Hydro Flame Corporation

Atwood Systems and Controls

Franco Consadori

Yousheng Shen

D George Field

Richard W Slamka

Kevin D Banta

Konrad Colbow

Gary S Nichols

A highly accurate, long life, low cost gas sensor is disclosed, particularly useful for measuring carbon monoxide and other toxic gases in an environment. The gas sensor has a first, sensing electrode and a second, counting electrode. Positioned between the first and second electrodes is an ion conducting, solid electrolyte membrane. In response to the presence of a toxic gas introduced to the first electrode, an electric signal is produced between the first electrode and the second electrode. The electric signal changes in response to changes in the concentration of the toxic gas. Detection circuitry measures the electric signal to determine the concentration of the toxic gas. An electrically conductive, hydrophobic top membrane electrically connects the first electrode to the detection circuitry while preventing liquid water from contacting the first electrode. An electrically conductive, hydrophobic bottom membrane electrically connects the second electrode to the detection circuitry. The top and bottom membranes, though hydrophobic, are preferably also microporous so as to be gas permeable, including permeable to water vapor. Preferably the top and bottom membranes are ion insulating as well. Optionally the sensor is provided with a water reservoir to maintain constant relative humidity at the ion conducting electrolyte membrane. The sensor may also have a heating element. Internal and external self-diagnostic features to ensure that the sensor is functioning normally are disclosed, as well as self-calibration features, so as to ensure sensor accuracy.

Gas sensor with electrically conductive, hydrophobic membranes

Gas sensor with a diagnostic device

A highly accurate, long life, low cost gas sensor is disclosed, particularly useful for measuring oxygen in an environment. The gas sensor has a first, sensing electrode and a second, counting electrode. Dual electrolytes are electrically serially connected between the first and second electrodes. One of the electrolytes is an ion conducting solid electrolyte, the second is a liquid electrolyte. In response to an electric current an electrical characteristic is produced, and the electrical characteristic changes in response to changes in the concentration of a gas such as oxygen introduced at the first, sensing electrode. The solid electrolyte can be a perfluorinated polymer which advantageously controls the rate of the electrochemical reaction to give the sensor a long life without need for continuous recalibration. A dense liquid impermeable membrane may be positioned over the first electrode so that only gas reaches the first electrode and all gas that reaches the first electrode passes through the membrane. Advantageously, the solid electrolyte isolates the liquid electrolyte from the first, sensing electrode. The liquid electrolyte may comprise an acidic solution, a basic solution or a salt solution.

Gas sensor with dual electrolytes

A low cost room temperature electrochemical gas sensor with humidity compensation for sensing CO, alcohol vapors and other toxic analyte gases has a solid protonic conductive membrane with a low bulk ionic resistance. A sensing electrode and a counter electrode, optionally a counter electrode and a reference electrode, which are separated by the membrane, can be made of mixed protonic-electronic conductors, or can be made of a thin electrically conducting film such as platinum. A reservoir of water maintain the solid protonic conductive membrane at constant 100 percent relative humidity to compensate for ambient humidity changes. Embodiments of the inventive sensor also include an electrochemical analyte gas pump to transport the analyte gas away from the counter electrode side of the sensor. Analyte gas pumps for the inventive sensor include dual pumping electrodes situated on opposite sides of the membrane, and include a means for applying a DC power across the membrane to the sensing and counter electrodes. Another embodiment of the inventive sensor has first and second solid protonic conductive membranes, one of which has a sensing electrode and a counter electrode separated by the first membrane, and the other of which has dual pump electrodes situated on opposite sides of the second membrane.

Low cost room temperature electrochemical carbon monoxide and toxic gas

A gas fired appliance measures infrared emissions from a metal object heated in a combustion chamber to evaluate combustion. Associated circuitry uses the evaluation to control operational parameters of the appliance, including fuel and air fed to the appliance. A second metal object, prior to fuel ignition, is electrically heated to emit infrared radiation. Infrared emissions from the second metal object, indicative of the temperature thereof, are monitored to assure an ignition temperature to ignite a combustible air and fuel mixture. A fan directs a stream of ambient air upon the second metal object to cool the same and reduce the infrared emanating therefrom. The reduction in infrared from the second metal object is monitored to verify proper fan operation.

Gas fired appliance igntion and combustion monitoring system

A low cost room temperature electrochemical gas sensor for sensing CO and other toxic analyte gases has a solid protonic conductive membrane with a low bulk ionic resistance. A sensing electrode and a count counter electrode, which are separated by the membrane, can be made of mixed protonic-electronic conductors. Embodiments of the inventive sensor also include an electrochemical analyte gas pump to transport the analyte gas away from the counter electrode side of the sensor. Analyte gas pumps for the inventive sensor include dual pumping electrodes situated on opposite sides of the membrane, and include a means for applying a DC power across the membrane to the sensing and counter electrodes. Another embodiment of the inventive sensor has first and second solid protonic conductive membranes, one of which has a sensing electrode and a counter electrode separated by the first membrane, and the other of which has dual pumping electrodes situated on opposite sides of the second membrane.

Gas sensor based on protonic conductive membranes

A system and method for using a gas detecting device that conducts electricity increasingly for increasing concentration of a gas being detected. The temperature of a gas sensor element is regulated to first burn-off impurities on the surface thereof, and then to cool down the gas sensor element to a temperature at or above which the gas catalyzes. During catalyzation, the sensor element conducts and electrically signals a microprocessor concentration data, which microprocessor controls a three color LED so as to emit a color pattern indicative of the concentration level of the gas. A sum of previously measured concentration levels is taken to gauge exposure to the gas over a period of time. The gas detection system includes a self-calibration routine that can be run prior to normal use by successive exposure to varying concentrations of gas to determine the sensor element-specific reaction. The sensor element output at each known concentration level is stored in nonvolatile memory during the self-calibration routine, which stored calibration data is compared to values measured during normal operation to accurately detect gas concentration levels. Audible alarms sound when the sum of previously measured concentration levels exceeds a predetermined hazardous level.

Method and system for gas detection

Gas is supplied to a gas flow modulator having a tubular member with a gas flow passage extending through the tubular member. A slide member in the gas flow passage is axially slidable longitudinally along the passage. Springs within the tubular member in opposite directions on the slide member so as to resiliently bias the slide member towards a predetermined position in the gas flow passage. A flow constrictor means is fixedly positioned within the gas flow passage for constricting gas flow along the gas flow passage, the slide member and the flow constrictor means being shaped to cease the flow of gas along the gas flow passage upon displacement of the slide member in a first direction from the predetermined position by means of an electromagnetic induction coil extending around the exterior of the tubular member and in cooperation with a magnetic material forming at least part of the slide member or secured thereto. The gas flow modulator may be used in a water heating system where a temperature sensing means senses water temperature to in turn control a power source to the induction coil so as to regulate the burning of gas at a gas burner in communication with the gas flow modulator. The slide member is prevented from sticking in the tubular member by rectifying or modulating the power signal to the induction coil which causes the slide member to vibrate.

Gas flow modulator

A gas sensing device has a sampling chamber for containing a gas to be sensed, with a gas sensing element with the chamber for providing an output signal which varies in response to the presence of the gas in the chamber. An orifice, or other restriction, permits gas flow between the interior and the exterior of the chamber and a pump, e.g. in the form of a heater, displaces a sample of the gas through the restriction into the interior of the chamber for sensing by the sensing element and subsequently displaces gas from the interior to the exterior of the chamber.

Growing community of inventors

Salt Lake City, UT, United States of America

Franco Consadori