A constant flow filter air sampler for workplace environments

Journal Article · Sun Dec 01 04:00:00 EST 1996 · Health Physics

DOI:https://doi.org/10.1097/00004032-199612000-00003· OSTI ID:420438

Parulian, A ^[1]; Rodgers, J C ^[2]; McFarland, A R ^[1]

---

1. Texas A&M Univ., College Station, TX (United States)
2. Los Alamos National Lab., NM (United States)

A filter air sampler has been developed for sampling radionuclide aerosol particles form the workplace environment. It provides easy filter changing, constant flow sampling, and a visual display to indicate proper operation. An experimental study was conducted to characterize the collection efficiency of the sampler as affected by variations in room air velocity, particle size, sampling flow rate, inlet geometry, and inlet orientation to the free stream. Tests were carried out in a wing tunnel at velocities between 0.3 m s{sup {minus}1} and 2.0 m s{sup {minus}1}, which is a range that covers anticipated velocities in the typical highly ventilated workplace environment of a nuclear facility. Nearly monodisperse aerosols with sizes between 5 and 20 {mu}m aerodynamic diameter were sampled at flow rates between 28.3 and 84.9 L min{sup {minus}1}. Inlet orientations of 0{degree}, 90{degree}, and 180{degree} from the horizontal were selected for evaluation. When the sampler was oriented at 0{degree} over various ranges of free stream velocities, sampling flow rates and particle sizes, the transmission efficiency of aerosol was typically greater than 95%. The transmission efficiencies varied form 80% to 106% for 10-{mu}m aerodynamic diameter particles over the previously noted range of free stream velocities and inlet orientations. Uniformity of deposits of 10 {mu}m aerodynamic diameter particles on collection filters was examined for a sampling rate of 57 L min{sup {minus}1}, a sampler orientation of 90{degree} into the wind and wind speeds of 0.3-2 m s{sup {minus}1}. The coefficients of variation for the areal density of the deposits ranged from 6.1% to 37.2%. A miniature critical flow venturi with a constant sampling flow rate of 57 L min{sup {minus}1} was developed for application to the new filter air sampler. It was demonstrated that the performance of the new filter air sampler is quite acceptable over a wide range of conditions. 31 refs., 8 figs., 1 tab.

• Sponsoring Organization: USDOE
• OSTI ID: 420438
• Journal Information: Health Physics, Journal Name: Health Physics Journal Issue: 6 Vol. 71; ISSN HLTPAO; ISSN 0017-9078
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
AIR FILTERS
AIR SAMPLERS
CRITICAL FLOW
OCCUPATIONAL SAFETY
PARTICLE SIZE
RADIOACTIVE AEROSOLS
SAMPLING
WIND