Abstract: Hydrazine vapors are electrochemically detected and measured by an apparatus comprising in combination intake means, an electrochemical cell, means for drawing said gas through said intake means and into said electrochemical cell, communicating means communicating said intake means with said cell, at least the internal surfaces of said intake means, said communicating means and said cell being of an inert material, the electrochemical cell comprising a sensing electrode, a counterelectrode, a reference electrode at which substantially no current flows, and an aqueous alkaline electrolyte in contact with said sensing electrode comprising a noble metal catalyst bonded to a hydrophobic material to provide a diffusion electrode, means for exposing said sensing electrode to said gas, means electrically coupled to said sensing electrode for maintaining said sensing electrode at a fixed potential of about 0.7 volt to about 1.

Abstract: Noxious gases are electrochemically detected and measured in the presence of carbon monoxide using a device employing an electrochemical cell whose sensing electrode comprises a carbon supported gold catalyst and is maintained at a fixed potential of about 0.4 volt to about 1.5 volt with respect to a reversible hydrogen electrode in said electrolyte of the electrochemical cell. In its preferred form the sensing electrode comprises carbon particles containing catalytic amounts of gold bonded to a hydrophobic material to provide a diffusion electrode.

Abstract: Carbon monoxide in gaseous samples containing hydrogen is detected by first heating the gas sample in an oxidizing atmosphere at a temperature of at least 700.degree. C. in a non-catalytic reaction zone to selectively oxidize the hydrogen to water and then passing the gaseous reaction products from the selective oxidation to a carbon monoxide analyzer.

Abstract: In the detection and measuring of NO, NO.sub.2 and mixtures thereof, a unit comprising in combination intake means, an electrochemical cell, means for drawing the gas through said intake means and into said electrochemical cell at a controlled flow rate, readout means for reading the quantity of gas detected, the electrochemical cell comprising an anode, a cathode, a reference electrode at which substantially no current flows and an aqueous electrolyte in contact with said anode, cathode and reference electrode, means for exposing said anode to said gas, means for maintaining said anode at a fixed potential relative to the reference electrode in excess of 1.5 V up to about 1.9 V with respect to a reversible hydrogen electrode in said electrolyte of said first electrochemical cell, the anode of said first electrochemical cell comprising a gold catalyst bonded to a hydrophobic material to provide a diffusion electrode.

Abstract: Noxious gases are electrochemically detected and measured in the presence of carbon monoxide using a device employing an electrochemical cell whose sensing electrode comprises a carbon supported gold catalyst and is maintained at a fixed potential of about 0.4 volt to about 1.5 volt with respect to a reversible hydrogen electrode in said electrolyte of the electrochemical cell. In its preferred form the sensing electrode comprises carbon particles containing catalytic amounts of gold bonded to a hydrophobic material to provide a diffusion electrode.

Abstract: The present invention relates to a device and method for the detection and measurement of nitrogen dioxide (NO.sub.2) and nitric oxide (NO) in a gaseous medium.

Abstract: An electrochemical cell comprising an anode, a cathode and a reference electrode operating in an aqueous electrolyte is utilized for detection of noxious gases in air. The gas is oxidized at the anode and detection thereof occurs as a result of the current generated by the reaction. A fixed potential difference is maintained between the anode and the reference electrode to avoid generation of undesired current from reactions involving an oxygen-water redox couple within the cell which would invalidate anode-cathode current for gas detection purposes. The fixed potential is chosen from within the range of about 0.9 to 1.5 volts.