Abstract: A gas analyzer is provided which is comprised of two gas sample flow loops joined at an angle to each other, one being an eductive loop that originates and returns to the chamber or conduit from which a gas sample is to be drawn and the other being a convective loop that joins in fluid flow communication with the eductive loop at a point upstream from its eductor device.

Abstract: An eductive flow loop has an inlet leg conduit projecting into an exhaust stack and an outlet leg conduit. A sample of gaseous combustion by-products is withdrawn from the exhaust stack into the inlet leg conduit and flows to the outlet leg conduit. A portion of the sample is drawn through a convective flow loop conduit and a gas sensing device and back to the outlet leg conduit and therefrom back into the exhaust stack. A counterflow device is positioned in the outlet leg conduit between the exhaust stack and the convective flow loop conduit. The counterflow device includes a portion of the outlet leg conduit that communicates with the exhaust stack and a blowback conduit connected to the outlet leg conduit. A stop member is movably positioned in the blowback conduit. When the fluid pressure in the blowback conduit is greater than the pressure of the gas sample flow, the stop member moves into the outlet leg conduit to block flow to the exhaust stack.

Abstract: A gas analyzer is provided with a common inlet-outlet chamber through which all gases must travel to enter or exit the flow circuit.

Abstract: A gas analyzer is provided which is comprised of two gas sample flow loops joined at an angle to each other, one being an eductive loop that originates and returns to the chamber or conduit from which a gas sample is to be drawn and the other being a convective loop that joins in fluid flow communication with the eductive loop at a point upstream from its eductor device.

Abstract: The moisture content of a gaseous mixture containing oxygen and the amount of other constituent gases in said mixture are determined by measuring, with an electrochemical cell, the ratio of oxygen partial pressures of a sample flow of said mixture and a comparison flow of a mixture of gases differing from said sample flow only by the reduction of the moisture content to a known level or, if moisture is not present, the reduction to a known level of the content of such other gaseous constituent. Also, provision is made to permit determining the amount of free oxygen in said gaseous mixture.