The Impinger Dust Sampling Apparatus as Used by the United States Public Health Service

Development of a fibre size-specific job-exposure matrix for airborne asbestos fibres

“…The impinger method for measurement of airborne dusts, including asbestos, was developed by the USPHS in the 1920s and measured all particles less than 10 μm in diameter (that is, those considered respirable) by low power, optical microscopy and expressed dust concentrations as millions of particles per cubic foot of air (mppcf) 11. In the 1960s the impinger began to be replaced by the membrane filter sampling method with counts of fibres longer than 5 μm being done by PCM and with fibre concentrations being reported as fibres longer than 5 μm per cubic centimetre of air (fibres/cm 3 ) 12 – 15.…”

The Preparation and Measurement of the Concentration of Dilute Bacterial Aerosols.

“…With it, collection efficiency appears uncertain (14). ^^aslfing j'^e^^ier these methods is adapted for the study of dilute aerosols, composed of dead bacteria, since particles cannot be readily counted without concentration and transfer (36,37). It is difficult to be certain that this procedure is rigorously quantitative.…”

Characterizing and Controlling Industrial Dust: A Case Study in Small Particle Measurement

“…This program pursued better field measurements of industrial dusts and in 1925 published a comparison of various instruments and measurement methods, documenting tests conducted jointly with the Bureau of Mines and the American Heating and Ventilating Engineers (Fieldner et al, 1925). In 1932, Greenberg and OIHS colleague George Smith reported on their development of the Greenberg-Smith impinger, an instrument capable of collecting airborne particulates which they later modified to collect samples of air from workers' breathing zones (Greenberg and Bloomfield, 1932). Over the next forty years, PHS and other researchers used this impinger method of collecting workplace samples of airborne dusts extensively (Cralley, 1996, p. 148).…”