Abstract: A gas detection device is provided comprising an exterior housing in which an active pelement and a compensating pelement are disposed. The gas detection device further comprises a porous frit seated within a distal end of the exterior housing to separate the active pelement and the compensating pelement from the surrounding environment. The porous frit is adapted to prevent flashback into the surrounding environment while allowing movement of environmental gas through the porous frit to contact the active pelement and the compensating pelement. The gas detection device further comprises a flow guide for directing flow of environmental gas into the gas detection device disposed adjacent the exterior side of the porous frit. The flow guide comprises an inlet port through which a forced flow of environmental gas is pumped to pass through the porous frit and into the exterior housing in a direction generally parallel to the axis of the exterior housing.

Abstract: A simple potentiostat circuit for use in biasing a three-electrode electrochemical cell is described wherein a direct electrical connection is made between the sensing electrode and the reference electrode during normal operation of the cell. Preferably the electrical connection is a resistor. By selecting the resistive value properly, the zero gas current of the cell is eliminated without negatively affecting the response of the cell.

Abstract: A one-step process is provided for the synthesis of organohaloboranes, including diisopinocampheylchloroborane, and alkoxyorganoboranes. The present process does not utilize a thermally unstable ether adduct or a malodorous dimethyl sulfide adduct as required in prior processes. In general, the organohaloboranes are synthesized in a single reactor by reacting olefin(s) and/or alkyne(s) with boron trihalide and diborane. Alkoxyorganoboranes are synthesized in a single reactor by reacting olefin(s) and/or alkyne(s) with alkylborate and diborane.

Abstract: A one-step synthesis of an alkali-metal hexamethyldisilazane is provided in which an alkali metal selected from the group consisting of lithium, sodium and potassium is reacted with 1,1,1,3,3,3,-hexamethyldisilazane at a reaction temperature above the melting point of the alkali metal without the use of an electron carrier, alkali-metal derivatized reagents, such as alkyl-aryl organometals, alkali-metal amides and alkali-metal hydrides, or a catalyst.

Abstract: A matched catalytically inactive compensator for use in a combustible gas sensor is made from a catalytically active detector. The catalytically active detector is exposed to a gas phase catalytic inhibitor such as hexamethyldisiloxane to completely destroy its catalytic ability thereby forming a compensator which has very similar chemical and physical properties to the untreated detectors.

Abstract: A personal sampling apparatus having multiple sampling ports for simultaneously taking a plurality of ambient air samples in parallel. Incorporated into the sampling apparatus is a regulator for enabling the apparatus to function with virtually any personal sampling pump. The regulator by being located immediately proximate to the sampling ports is able to provide independent vacuum flow rate control of each of the multiple sampling ports.

Abstract: A compact electrochemical gas sensor for detecting toxic gases is described which utilizes a fluted electrically-conducting feedthrough for making the electrical connection from outside the sensor with each electrode inside the sensor. Utilization of the fluted electrically-conducting feedthroughs significantly reduces the number of parts needed to make the sensor as well as reduces the likelihood of electrolyte leakage from the sensor. Additionally, the electrochemical toxic gas sensor may use a gas permeable membrane instead of a gas porous membrane.

Abstract: A portable sampling pump apparatus including a flow control mechanism having a laminar flow meter for providing a precise readout of the volumetric flow rate of the pump as well as feedback control for the pump motor. The pump apparatus includes an electric motor, a pump operably driven by the electric motor, a laminar flow element positioned in a flow path of the pump, a pressure transducer for sensing a pressure drop across the laminar flow element and for producing an electrical signal that is directly and linearly proportional to the volumetric flow rate through the pump, and a motor control circuit which uses the electrical signal to control the voltage applied to the motor and to thereby regulate the flow of the pump. This electrical signal is also used to generate a display for the user of the volumetric flow of the pump.