To insure a wide dissemination of information describing advances in measurement and control techniques, the Instrument Society of America (ISA) has published this monograph of selected papers, the second in a series, from recent ISA symposia dealing with air pollution. Papers range from a discussion of individual pollutant measurements to discussions of sample conditioners, calibration methods and devices, and data acquisition systems. Titles include: Energy Dispersive X-Ray Emission Spectrometry for Multielement Analysis of Air Particulates; Applications of a Precision Ozone Generator in Calibration of Ozone/Oxidant Analyzers and Inlet-Sample Air; Use of an Automated Gas Chromatograph in Smog Chamber Studies; The Wickedness of Air Pollution Measurements; A Motor Vehicle Emissions-Monitoring and Inspection System; Qualification Testing of an Infrared Analyzer System for SO2 and NO in Power Plant Stack Gas; Ringelmann Numbers and the Law; Experience with Industrial Hygiene and Air Monitoring Equipment; Variable Dilution Interface System for Source Pollutant Gases; Continuous Monitoring of Stack Gases; Pollution Abatement - More Than Meets the Eye; Calibrating Trace Gas Analyzers Using Permeation Tubes; A High Specificity Carbon Monoxide Analyzer; Fluidic Sensors to Measure Velocities Under Adverse Conditions; and A Continuous Ultraviolet Absorption Ozone Photometer. (BT)