Analysis of sampling line bias on respirable mass measurement.
Appl Occup Environ Hyg
; 18(6): 458-65, 2003 Jun.
Article
en En
| MEDLINE
| ID: mdl-12746069
This study investigated the bias introduced by an inlet sampling line on a respirable mass monitor. The 1.5-m electrically conductive, flexible sampling line conducts aerosol at a flow rate of 2.2 Lpm from a helmet-mounted inlet to a waist-mounted sensor for mass concentration measurement. Particulate transport was modeled for each section of the sampling line and considered the effects of diffusion, gravitational settling, and inertial impaction. An estimate of respirable mass concentration measured with the sampling line was determined by integrating assumed workplace aerosols with the transport curves. The bias introduced by the sampling line was then calculated by dividing the difference between the respirable mass concentration with and without the sampling line by that without the sampling line. For the current sampling line, in which the inner diameter is 4.83 mm, bias was calculated as -0.3 percent, -2.4 percent, -4.6 percent, and -6.7 percent for four test aerosols with mass median aerodynamic diameters of 0.6 microm, 4 microm, 12 microm, and 30 microm, respectively. Optimization studies suggest that increasing the sampling line with a larger inner diameter by a factor of 1.25 to 1.75 will minimize bias to below -3.0 percent. An experimental study confirmed that bias due to the presence of the sampling line is small.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Monitoreo del Ambiente
/
Carbón Mineral
/
Contaminantes Ocupacionales del Aire
/
Polvo
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
Appl Occup Environ Hyg
Asunto de la revista:
MEDICINA OCUPACIONAL
/
SAUDE AMBIENTAL
Año:
2003
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Reino Unido