Performance Comparison of Real-Time Light Scattering Dust Monitors Across Dust Types and Humidity Levels
Video techniques for monitoring exposure, such as NIOSH’s “Helmet-CAM,” employ both real-time dust monitors and mobile video cameras to assess workers’ respirable dust exposures. Many real-time personally worn dust monitors utilize light scattering sensing elements, which are subject to measurement biases as a function of dust type (size, composition, shape factor) and environmental conditions such as relative humidity. These biased and inaccurate dust measurements impair the monitor’s ability to properly represent actual respirable dust concentrations. In the testing described, instrument mass concentration data was collected using three different types of commonly used commercial off-the-shelf personal dust monitors and compared to a reference standard. This testing was performed in a calm air (Marple) dust chamber in which three units of each make and model (for a total of nine monitors) were used for each test. Equivalency factors (EF, a multiplier to match the Thermo TEOM 1400a reference instrument) ranged between 0.746 and 1.879 across all dusts and environmental conditions tested, and between 0.821 and 1.519 on the ISO test dust.
KeywordsLight scattering instrument Industrial mineral dusts Respirable dust sampler Aerosol sampling methods Equivalency factor
We are grateful to NIOSH researcher James Noll who helped to design and pilot studies in this area. We also appreciate the experience and expertise of NIOSH technicians Joe Archer and Jeanne Zimmer (both retired) for their execution of the tests in the Marple chamber and handling of the gravimetric filters. Finally, we thank Jarod Myers for conducting the bulk particle sizing.
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
The findings and conclusions in this paper are those of the authors and do not necessarily represent the official position of the National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention. Mention of any company or product does not constitute an endorsement by NIOSH.
- 1.McWilliams LJ, Lenart PJ, Lancaster JL, Zeiner Jr JR (2012) National survey of the mining population part 1: employees. Office of Mine Safety and Health Research, Information Circular, IC, 9527, 252Google Scholar
- 2.MSHA (2017) MSHA Data Sets; Personal Health Samples. Retrieved from https://arlweb.msha.gov/OpenGovernmentData/OGIMSHA.asp
- 3.Cecala AB, O'Brien AD (2014) Here comes the Helmet-CAM: a recent advance in technology can improve how mine operators investigate and assess respirable dust. Rock Prod 117:26–30Google Scholar
- 4.Haas EJ (2018) How health & safety professionals can use EVADE Software to assess worker exposure. (DHHS (NIOSH) Publication No. 2018-108d). Retrieved from https://www.youtube.com/watch?v=tQdaE9ronqg
- 5.NIOSH (1994) NIOSH, Manual of Analytical Methods: US Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Physical Sciences and EngineeringGoogle Scholar
- 6.Reed WR, Potts JD, Cecala AB, Archer WJ (2012) Use of the 1500-pDR for gravimetric respirable dust measurements at mines. SME TransactionsGoogle Scholar
- 7.Chu B (2007) Laser light scattering: basic principles and practice: Courier CorporationGoogle Scholar
- 8.Mishchenko MI, Hovenier JW, Travis LD (1999) Light scattering by nonspherical particles: theory, measurements, and applications: ElsevierGoogle Scholar
- 9.Williams KL, Timko RJ (1984) Performance evaluation of a real-time aerosol monitor (Information Circular 8968)Google Scholar
- 11.Thorpe A, Walsh PT (2002) Performance testing of three portable, direct-reading dust monitors. Ann Occup Hyg 46(2):197–207Google Scholar
- 12.Thorpe A, Walsh PT (2007) Comparison of portable, real-time dust monitors sampling actively, with size-selective adaptors, and passively. Ann Occup Hyg 51(8):679–691Google Scholar
- 13.TSI (2015) Custom Cal Factor for Diesel Particulate Matter (DPM)Google Scholar
- 15.Scientific Corporation, Thermo Scientific (2013) Model pDR-1000AN/1200 personalDATARAM Instruction ManualGoogle Scholar
- 17.Volkwein JC, Vinson RP, Page SJ, McWilliams LJ, Joy GJ, Mischler SE, Tuchman DP (2006) Laboratory and field performance of a continuously measuring personal respirable dust monitorGoogle Scholar
- 19.Listak JM, Checkan GJ, Colinet JF, Rider JP (2007) Performance of a light scattering dust monitor at various air velocities: results of sampling in the active versus the passive mode. Int J Miner Res Eng 12(1):35–47Google Scholar
- 20.Neter J, Kutner MH, Nachtsheim CJ, Wasserman W (1996) Applied linear statistical models (Vol. 4): Irwin ChicagoGoogle Scholar
- 21.Natrella M (2012) NIST/SEMATECH e-handbook of statistical methods. http://www.itl.nist.gov/div898/handbook, 11/30/2018