Page 185 - Instrumentation Reference Book 3E

Further reading 169
Optical techniques may not be appropriate since British Standards, Methods for tlie Deterrninntion of
these tend to give the “smoothed” surface area Particle Six Distribution. BS 3406 Parts 1-7
rather than the true surface area-including Hinds, W. C., Aerosol Technology: Propevties, Behavior
roughness and pores. Some gases adsorb onto and Measwenzent of Airborne Particles, Wiley, Chi-
Chester, UK (1982)
the surface of substances, i.e., they form a layer Silverman, L.: Billings, C. E., and M. W. First, Particle
which may be only one molecule thick on the Six Analysis in Industrial Hygiene, Academic Press,
surface. This is not to be confused with absorp- New York (1972)
tion in which the substance is porous and the Willeke. K. and P. Baron (eds) Aerosol Measurenzent:
gases penetrate the substance. The subject is too Principles, Techniqiies and Applications, Van Nos-
large for a. complete treatment here. The principle trand. New York
is that the particles are first “cleaned” of all pre-
vious adsorbates and then treated with a specific 11.11 Further reading
adsorbate, e.g., nitrogen, which is then measured
by difference from the adsorbate source. If the Barth, H. G., Modein Methods qfPavticle Sire Annlj,sis.
layer is monomolecular, the surface area is read- Wiley, Chichester, UK (1984)
ily calculated; corrections have to be applied Berhardt, I. C.: Prirticle Size Analysis: Classificiition and
because this is generally not the case. Results Sedimentation Techniques, Chapman & Hall, London
are given in terms of surface aredvolume or sur- (1994)
face arealmass. Hireleman, E. D.. W. D. Bachalo, and P. G. Felton
(eds), Liquid Particle Sire A~ensirr.a~eiit Teclzniques,
Vol 2, American Society for Testing and Materials,
References Philadelphia. PA (1990)
Syvitski, J. P. M. (ed.). Principles, Methods rind Applica-
Allen, T., Parficle Six Measuvenzenr. Chapman & Hall, tions of Pnrticle Size Analysis, Cambridge University
London (1981) Press, Cambridge (1991)