Abstract: A poison resistant combustible gas sensing element, a method for its production and a method for determining poisoning of the element. The element includes an electric heating element, an inner layer coated on the electric heating element and containing a precious metal catalyst supported on a porous oxide, the precious metal catalyst catalyzing combustion of a combustible gas to be detected by the element, and an outer layer overlaying the first layer, and containing a catalytic compound capable of trapping gases which poison the precious metal catalyst, the catalytic compound being supported on a porous oxide.

Abstract: A poison resistant combustible gas sensing element, a method for its production and a method for determining poisoning of the element. The element includes an electric heating element, an inner layer coated on the electric heating element and containing a precious metal catalyst supported on a porous oxide, the precious metal catalyst catalyzing combustion of a combustible gas to be detected by the element, and an outer layer overlaying the first layer, and containing a catalytic compound capable of trapping gases which poison the precious metal catalyst, the catalytic compound being supported on a porous oxide.

Abstract: A calibration adaptor for a gas sensing device having a gas entry port therein includes a base piece having a gas entry port therein which is fixedly attached to a surface of the gas sensing device, and provided with means for releasably retaining the base piece in a first position in which the gas entry port of the gas sensing device is open to detect ambient gases, and means for moving the attached base piece to a second position in which the gas entry port of the base piece is aligned with the gas entry port of the gas sensing device, and controls entry of gas into the gas entry port of the gas sensing device. A calibration gas source may be attached to the gas entry port of the base piece.

Abstract: A calibration adaptor for a gas sensing device having a gas entry port therein includes a base piece having a gas entry port therein which is fixedly attached to a surface of the gas sensing device, and provided with means for releasably retaining the base piece in a first position in which the gas entry port of the gas sensing device is open to detect ambient gases, and means for moving the attached base piece to a second position in which the gas entry port of the base piece is aligned with the gas entry port of the gas sensing device, and controls entry of gas into the gas entry port of the gas sensing device. A calibration gas source may be attached to the gas entry port of the base piece.

Abstract: A poison resistant combustible gas sensing element, a method for its production and a method for determining poisoning of the element. The element includes an electric heating element, an inner layer coated on the electric heating element and containing a precious metal catalyst supported on a porous oxide, the precious metal catalyst catalyzing combustion of a combustible gas to be detected by the element, and an outer layer overlaying the first layer, and containing a catalytic compound capable of trapping gases which poison the precious metal catalyst, the catalytic compound being supported on a porous oxide.

Abstract: A docking station for use with an environmental monitoring instrument to provide predictive diagnostic information. The docking station is connected, typically via the Internet, to a remote service center, and exposure data, calibration data and diagnostic data are communicated from the instrument to the docking station and from the docking station to the service center. Mathematical analysis of the collected data from all available sources is performed at the service center and predictive warnings are generated to alert the users of potential instrument faults, thus allowing preemptive maintenance. The analysis methods include principle component analysis and other statistical methods, fuzzy logic and neural networks. This docking station can be used with monitoring instruments for water quality, pollution control, indoor air quality and breathing air quality.

Abstract: An oxygen sensor based on a metal-air cell, typically a commercially available zinc-air battery of the type used in hearing aids. The cell, which admits oxygen to generate electric current at its cathode is disposed in a mechanical housing which restricts the flow of oxygen to the cell, and is connected to an electrical circuit which provides a variable resistance load, the load increasing as current flow through the circuit decreases, to prevent hydrogen evolution at the cathode. Current flow through the cell is measured, and is proportional to oxygen concentration.

Abstract: A method and apparatus for determining the concentration of a gas using nondispersive infrared absorption. The method includes measuring the output signal for a plurality of instantaneous time periods, calculating the change of the output signals (CS), calculating the change of the change of the output signal (CCS) which creates a pattern of CCS data and comparing the CCS data with corresponding CCS data for a known reference gas at a known concentration and at a range of known temperatures. The apparatus for determining the concentration of a known gas in a sample gas mixture is a gas chamber, a light source, a detector, a signal converter, and a data acquisition and microprocessor unit which measures the output signal and has a memory with a program to calculate the change of the signal (CS) and the change of the change of the signal (CCS), and compare the CCS data generated from the gas sample mixture to CCS data of known gases with known concentrations and at known temperature ranges.