Cincinnati, OH: American Conference of Governmental Industrial Hygienists, Publication Number ASI2, 2008 May; :1-26
This monograph reviews the calibration techniques relevant to aerosol samplers, such as sizing instruments, devices for measuring concentrations, and size selective samplers. Test facilities, generation of test aerosols, and testing procedures are emphasized. All sampling instruments require calibration. However, some instruments, such as photometers, rely on empirical calibrations using standard test aerosols. While the performance of other instruments, such as the optical particle counter, the impactor, and the condensation nucleus counter (CNC), can be described by theories that predict their instrument responses, their actual performance may differ from the theory because not all factors are taken into account in these theoretical models. For example, impactor cutoff diameters can be calculated for ideal sticky aerosols. However, such calculations do not take into account particle bounce, re-entrainment, electrostatic charge effects, and wall losses. Evaluation of the actual performance of the impactor requires experimental calibration. To obtain data that are of high quality, reproducible, and defensible for the intended purposes, instruments must be calibrated. Furthermore, such calibration must be appropriate to its application.