Encyclopedia of Environmental Science and Engineering, Volume I and II

52 AIR POLLUTION INSTRUMENTATION

Extractive Analyzers—Other Methods

There are a few special methods that do not fit into the

three general classifications of absorption spectrometers,

luminescence analyzers or electroanalytical methods.

Paramagnetism is used in some O 2 analyzers, and thermal

conductivity is used in some SO 2 continuous monitors.

Paramagnetic analyzers rely on the fact that O 2 mole-

cules are attracted by a magnetic field, and this attraction can

be quantified. However, it should be noted that NO and NO 2

are also paramagnetic, and in high enough concentrations

can interfere in the analysis.

Thermal conductivity analyzers utilize a heated wire

which undergoes resistance changes as gases flow over it.

CO 2 , SO 2 and other gases may be continuously monitored by

thermal conductivity.

Please refer to Table 2 for list of some extractive instru-

ment manufacturers.

IN-SITU ANALYZERS

Unlike an extractive monitor, an in-situ monitoring system

will directly measure gas concentrations in the stack without

TABLE 2 (continued)

Lists of extractive instrument manufacturers

2500 Harbor Boulevard

Fullerton, CA 92634

Process Instrument Division

PO Drawer 831

Lewisburg, WV 24901

Calibrated Instruments, Inc. Esterline Angus

731 Saw Mill River Road 19 Rozel Road

Ardsley, NY 10502 Princeton, NJ 08540

CEA Instruments (Peerless) Leeds & Northrop

555 Madison Avenue Sumneytown Pike

New York, NY 10022 North Wales, PA 19454

Horiba Instruments, Inc. MSA Instrument Division

1021 Duryea Avenue Mine Safety Appliances

Santa Ana, CA 92714 201 Penn Center Boulevard

Pittsburgh, PA 15208

Infrared Industries Teledyne-Analytical Instruments

PO Box 989 333 West Mission Drive

Santa Barbara, CA 93102 PO Box 70

San Gabriel, CA 91176

Extractive differential absorption analyzers

Teledyne-Analytical Instruments DuPont Company

333 West Mission Drive Instrument Products

PO Box 70 Scientific & Process Division

San Gabriel, CA 91776 Wilmington, DE 19898

CEA Instruments Esterline Angus

555 Madison Avenue 19 Rozel Road

New York, NY 10022 Princeton, NJ 08540

Western Research and Development Ltd

Marketing Department

No. 3. 1313 44th Avenue NE

Calgary, Alberta T2E GL5

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