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 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.

Abstract: A hand-held air sampling pump can be operated with one hand to consistently sample an exact, predetermined volume of air by causing a bellows to compress and then elongate to form a vacuum inside of the bellows to draw an air sample through a detector tube and into the bellows.

Abstract: A liquid separator for removing liquid from a breath sample comprises a liquid trap having a conduit passing the breath sample and opening through a check valve to a reservoir chamber. Sample flow is diverted to the reservoir and ambient air is drawn back through the conduit and check valve to backflush liquid in the conduit to the reservoir. The reverse flow is activated by the presence of liquid in the sample line, periodically actuated by a timer or both. The reverse air flow may be used as a zero calibration gas for an infrared analyzer.

Abstract: A liquid separator for removing liquid from a breath sample comprises a liquid trap having a conduit passing the breath sample and opening through a check valve to reservoir chamber. Sample flow is diverted to the reservoir and ambient air is drawn back through the conduit and check valve to backflush liquid in the conduit to the reservoir. The reverse flow is activated by the presence of liquid in the sample line, periodically actuated by a timer or both. The reverse air flow may be used as a zero calibration gas for an infrared analyzer.

Abstract: A catalytic gas detector circuit in which a resistive gas detector element is common to two bridge circuits, and wherein the resistance and temperature of the detector element are maintained essentially constant. This permits the use of a dynamic compensator element without encountering hysteresis effects and improves the response time of the circuit.

Abstract: An atmospheric sampling pump arrangement employing a mass flow sensor which electronically monitors mass flow and compares it to a set-point value. The pump is then controlled in a manner that will minimize the difference between the measured flow and the set-point value. When the flow output drops below a predetermined value, a signal is energized to indicate the inability to maintain the desired flow. The system also incorporates a timer circuit which counts up the total amount of time that loss of flow regulation exists. After a predetermined period of cumulative loss of flow regulation, typically 30 minutes, a signal is energized to indicate this condition.

Abstract: A carbon monoxide removing catalytic material is disposed in one end of a first hollow column having open ends while porous inactive material is disposed in one end of a similar second column to offer substantially the same resistance to air flow as the catalytic material. There is a bed of regenerable air-drying substance in each column between the other material therein and the opposite end of the column. The volume and resistance to air flow of the two beds is substantially the same. Valve means connect an air stream with said opposite end of the first column and simultaneously connect said end of the second column with the atmosphere. Conduit means connect the other ends of the columns with each other, with an outlet port between the columns connected with the inlet of a pressure regulator.