Abstract: A system and apparatus for analyzing stack gas for total reduced sulfur. The gas is withdrawn from a stack through a probe, filtered and regulated to a known temperature. The gas is then passed through a scrubbing column to remove sulfur dioxide and split into first and second portions. The first portion is oxidized to covert total reduced sulfur compounds to SO2, and the gas is then passed to an electrochemical sensor for SO2 which is maintained at a temperature at least equal to the temperature of the regulated gas. The second portion of the scrubbed gas is passed through an electrochemical sensor for oxygen which is maintained at substantially the same temperature as the sensor for SO2.

Abstract: A method and apparatus for sampling and dilution of a process gas stream. A probe is inserted into the stream, the probe being open at its front end, and a precisely regulated flow of a dilution gas is inputted at a mid-point of the probe. A precisely regulated, and greater flow of unfiltered gas is withdrawn from the rear end of the probe. The difference between the input flow and the withdrawn flow is process gas which is diluted by the dilution gas, and the ratio of process gas to withdrawn flow can be precisely regulated.

Abstract: An inertial filtration dilution probe for sampling stack gas for analysis. The probe is based on a body having a central chamber passing from a first end of the body to a second end. One end of the central chamber is connected to a sampling tube to be inserted into a stack and the opposite end of the body has a port which is adapted to be selectively connected to a source of calibration gas or blowback gas. A filter divides the central chamber into an inlet portion and an outlet portion, with the sampling tube and port connected to the inlet portion. The probe further comprises a dilution eductor joined to the body, for mixing filtered stack gas with dilution gas and comprising an inlet for dilution gas, an outlet for diluted gas and a vacuum cavity therebetween. A sample passage within the body connects the outlet portion of the chamber to the vacuum cavity and a heating means encloses the body and eductor.

Abstract: The invention provides a method and apparatus for measuring the sodium sulfide content of liquid industrial process streams. According to this method, a sample of the liquid is passed through a heated filter to remove solids and reduce viscosity and a portion of the sample is then mixed with carbon dioxide to generate hydrogen sulfide gas. The hydrogen sulfide gas is separated from the reacted liquid sample, and a portion of the gas is mixed with dilution air and then analyzed quantitively for hydrogen sulfide.

Abstract: A method and apparatus are disclosed for measuring the gaseous content of industrial process gas streams. Gas is removed from the stream at a low flow rate, under 1 liter per minute, and is passed through a heated filter to remove particulates. The gas is then cooled to about 35.degree. to 70.degree. F. in order to condense water from the stream, and is passed through a metering pump which supplies a precisely metered amount of gas which can be mixed with air for dilution. The gas is then analyzed for the desired components.

Abstract: A gas sampling extractor for extracting a stack gas sample for analysis. The gas sampling extractor includes a filter housing and an eductor in combination with gas conditioning apparatus for sampling and conditioning the emission pollutant content of a gaseous medium in a stack prior to introducing the sample gas to a measuring instrument for further analysis thereof.

Abstract: A probe for obtaining particulate-free samples of gas from a smoke stack for a power plant or other industrial installation. The probe comprises a coarse filter, with means for periodic cleaning by blowback, protecting the inlet to an inertial filter. A high velocity flow of coarsely filtered stack gas is established through the inertial filter. Sample gas is withdrawn from the inertial filter at a low rate in a direction orthogonal to the gas stream through the inertial filter so as not to disturb particles in the inertial filter stream. The invention eliminates the necessity for frequent maintenance of stack mounted filters or other stack mounted components.