Abstract: An electrochemical sensor having at least two electrodes, and a reservoir chamber containing electrolyte. The reservoir chamber is internally coated with a wicking material to spread the electrolyte evenly over the walls of the reservoir.

Abstract: An electrochemical sensor having at least two electrodes, and a reservoir chamber containing electrolyte. The reservoir chamber is internally coated with a wicking material to spread the electrolyte evenly over the walls of the reservoir.

Abstract: An apparatus for providing a test gas to a gas monitoring instrument having a window for admitting gas to a gas sensor therein, is formed from a mechanical adaptor open at a portion thereof and having walls constructed and arranged such that the mechanical adaptor removably fits over the window to form a substantially gas tight chamber of predefined volume defined by the walls of the mechanical adaptor and the instrument, means disposed in the mechanical adaptor for receiving a vial of test gas and breaking a seal in the vial to admit the test gas to the chamber. The invention is also directed to a kit including the vial of test gas, and a method for testing a gas detection instrument utilizing the apparatus and a vial of test gas.

Abstract: An apparatus for providing a test gas to a gas monitoring instrument having a window for admitting gas to a gas sensor therein, is formed from a mechanical adaptor open at a portion thereof and having walls adapted to the gas monitoring instrument such that the mechanical adaptor removably fits over the window to form a substantially gas tight chamber of predefined volume defined by the walls of the mechanical adaptor and the instrument, means disposed in the mechanical adaptor for receiving a vial of test gas and breaking a seal in the vial to admit the test gas to the chamber. The invention is also directed to a kit including the vial of test gas, and a method for testing a gas detection instrument utilizing the apparatus and a vial of test gas.

Abstract: A digitally accessible sensor (DAS) assembly includes a sensor, such as a gas sensor, attached to a printed circuit board which includes an analog-to-digital converter, and a digital interface. This modular design significantly shortens the analog signal path from the sensor and provides digital information to the instrument microcontroller, and thereby reduces noise levels from the sensor and circuitry. The circuit board design also includes a non-volatile memory unit allowing retention of information related to the sensor and its operation and/or the application, and may include an amplifier for amplifying the low level analog signal.

Abstract: An apparatus for providing a test gas to a gas monitoring instrument having a window for admitting gas to a gas sensor therein, is formed from a mechanical adaptor open at a portion thereof and having walls constructed and arranged such that the mechanical adaptor removably fits over the window to form a substantially gas tight chamber of predefined volume defined by the walls of the mechanical adaptor and the instrument, means disposed in the mechanical adaptor for receiving a vial of test gas and breaking a seal in the vial to admit the test gas to the chamber. The invention is also directed to a kit including the vial of test gas, and a method for testing a gas detection instrument utilizing the apparatus and a vial of test gas.

Abstract: An apparatus for providing a test gas to a gas monitoring instrument having a window for admitting gas to a gas sensor therein, is formed from a mechanical adaptor open at a portion thereof and having walls adapted to the gas monitoring instrument such that the mechanical adaptor removably fits over the window to form a substantially gas tight chamber of predefined volume defined by the walls of the mechanical adaptor and the instrument, means disposed in the mechanical adaptor for receiving a vial of test gas and breaking a seal in the vial to admit the test gas to the chamber. The invention is also directed to a kit including the vial of test gas, and a method for testing a gas detection instrument utilizing the apparatus and a vial of test gas.

Abstract: An apparatus and method for generating a low concentration of gas within a carrier gas flow employing one or more miniature one-piece cylinders filled under pressure with a pure gas, or a concentrated gas balanced with an inert gas or gas mixture. Released from the cylinder through a pierced or other controlled opening, the flow of the gas is regulated by a pressure regulator and a micro orifice to be blended into a steady stream of diluent gas, typically ambient air, to form a desired gas concentration. No gas is generated if the pressure of the gas in the cylinder, which is monitored constantly by a pressure transducer, is below a predetermined level. The apparatus can be built into a portable device, or an automated docking station (or calibration station) for testing and calibrating gas detection and monitoring instruments, or into a fixed gas detection system for performing such functions.

Abstract: A gas detection instrument comprises a combustible gas sensor and associated circuitry, which supplies power to the sensor and measures and displays resulting sensor response. The supplied power is switched between timed pulses of electricity and steady state electricity, with the intermittent electricity being employed only when no significant change in sensor output has been detected. Alternatively, timed pulses of electricity are maintained, and predictive software algorithms are used to give readings for gas concentration during interruption of the power supply. The sensor operation enables the instrument to respond to rapid changes in gas concentration while minimizing power consumption of the sensor.

Abstract: An apparatus and method for generating a low concentration of gas within a carrier gas flow employing one or more miniature one-piece cylinders filled under pressure with a pure gas, or a concentrated gas balanced with an inert gas or gas mixture. Released from the cylinder through a pierced or other controlled opening, the flow of the gas is regulated by a pressure regulator and a micro orifice to be blended into a steady stream of diluent gas, typically ambient air, to form a desired gas concentration. No gas is generated if the pressure of the gas in the cylinder, which is monitored constantly by a pressure transducer, is below a predetermined level. The apparatus can be built into a portable device, or an automated docking station (or calibration station) for testing and calibrating gas detection and monitoring instruments, or into a fixed gas detection system for performing such functions.

Abstract: A gas detection instrument comprises a combustible gas sensor and associated circuitry, which supplies power to the sensor and measures and displays resulting sensor response. The supplied power is switched between timed pulses of electricity and steady state electricity, with the intermittent electricity being employed only when no significant change in sensor output has been detected. Alternatively, timed pulses of electricity are maintained, and predictive software algorithms are used to give readings for gas concentration during interruption of the power supply. The sensor operation enables the instrument to respond to rapid changes in gas concentration while minimizing power consumption of the sensor.

Abstract: A compact, long-lived oxygen sensor having an aqueous electrolyte and three gas diffusion electrodes, a working electrode, a reference electrode and a counter electrode. A porous, hydrophobic means is employed in conjunction with the counter electrode to allow air pressure in the sensor to be balanced with atmospheric pressure. The working and reference electrodes are further protected from contact with flow of electrolyte from the reservoir by a separator, so that the current output is fairly independent of sensor movement.

Abstract: An electrochemical sensor having electrolyte, at least two electrodes and an electrolyte reservoir in a housing. The sensor has a hydrophobic gas communication means between said electrodes, electrolyte reservoir and ambient atmosphere. An electrochemical sensor having hydrophobic communication means mounted between electrodes and extending down to the electrolyte reservoir of the electrochemical sensor. Either embodiment of the sensor can provide oxygen for operation of the sensor and a balance of pressure, without interfering or poisonous gases.

Abstract: A method and apparatus for diagnosing defects in electrochemical gas sensors, in which the water vapor pressure of the air surrounding a sensor is suddenly changed by changing to more dry or more humid air, thereby causing a sharp change in the acidity at the working electrode, and hence, a transient current from the sensor. The response of the sensor to the change in water vapor pressure is monitored and is used for sensor diagnostics. Lack of sensitivity of the sensor to the water vapor pressure change is an indication that the sensor does not have appropriate sensitivity to the gas to be detected. The method and apparatus are particularly useful for diagnostic testing of sensors without a gas filter.

Abstract: A method and apparatus for diagnosing defects in electrochemical gas sensors, in which the water vapor pressure of the air surrounding a sensor is suddenly changed by changing to more dry or more humid air, thereby causing a sharp change in the acidity at the working electrode, and hence, a transient current from the sensor. The response of the sensor to the change in water vapor pressure is monitored and is used for sensor diagnostics. Lack of sensitivity of the sensor to the water vapor pressure change is an indication that the sensor does not have appropriate sensitivity to the gas to be detected. The method and apparatus are particularly useful for diagnostic testing of sensors without a gas filter.

Abstract: An amperometric electrochemical gas sensor includes a permanent electrical resistance means disposed between two electrodes, one of which is the working electrode, the electrical resistance means having an electrical resistance of between about 10&OHgr; and 200 k&OHgr;. This resistance means provides a permanent shorting link between the electrodes, and constantly maintains the sensor in a ready-to-work condition.

Abstract: An amperometric electrochemical gas sensor includes a permanent electrical resistance means disposed between two electrodes, one of which is the working electrode, the electrical resistance means having an electrical resistance of between about 10 &OHgr; and 200 k&OHgr;. This resistance means provides a permanent shorting link between the electrodes, and constantly maintains the sensor in a ready-to-work condition.

Abstract: A simple, reliable, and leak-proof electrochemical sensor for detection of toxic gases. The sensor comprises a housing having an electrochemical gas sensor cell with an electrolyte and first and second electrodes bonded to conductive plastic. Each of the first and second electrodes is a membrane formed from a fluoropolymer film having a layer adhered thereto of a catalyst-impregnated fluoropolymer. The layers of each of said first and second electrodes are bonded to conductive plastic, and are separated by an absorbent material having an electrolyte absorbed therein. The sensor is particularly intended for detection of carbon monoxide, but may be used to detect other gases.

Abstract: A simple, reliable, and leak-proof three-electrode electrochemical sensor for detection of toxic gases. The sensor comprises a housing having an electrochemical gas sensor cell with an electrolyte and sensing, counter and reference electrodes bonded to conductive plastic. Each of the electrodes is a membrane formed from a fluoropolymer film having a layer adhered thereto of a fluoropolymer-impregnated catalyst. The layers of each of the electrodes are bonded to conductive plastic, and are separated by an absorbent material having an electrolyte absorbed therein. The sensor is particularly intended for detection of carbon monoxide, but may be used to detect other gases.