Characteristics of an aerosol photometer while automatically controlling chamber dilution-air flow rate

P T O'Shaughnessy; D R Hemenway

doi:10.1080/08958370050138021

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Characteristics of an aerosol photometer while automatically controlling chamber dilution-air flow rate

Journal article

Peer reviewed

Characteristics of an aerosol photometer while automatically controlling chamber dilution-air flow rate

P T O'Shaughnessy and D R Hemenway

Inhalation toxicology, Vol.12(10), pp.979-996

10/2000

DOI: 10.1080/08958370050138021

PMID: 10989372

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Abstract

Trials were conducted to determine those factors that affect the accuracy of a direct-reading aerosol photometer when automatically controlling airflow rate within an exposure chamber to regulate airborne dust concentrations. Photometer response was affected by a shift in the aerosol size distribution caused by changes in chamber flow rate. In addition to a dilution effect, flow rate also determined the relative amount of aerosol lost to sedimentation within the chamber. Additional calculations were added to a computer control algorithm to compensate for these effects when attempting to automatically regulate flow based on a proportional-integral-derivative (PID) feedback control algorithm. A comparison between PID-controlled trials and those performed with a constant generator output rate and dilution-air flow rate demonstrated that there was no significant decrease in photometer accuracy despite the many changes in flow rate produced when using PID control. Likewise, the PID-controlled trials produced chamber aerosol concentrations within 1% of a desired level.

Aerosols

Air Movements

Air Pollutants - analysis

Animals

Atmosphere Exposure Chambers

Automation - instrumentation

Feedback

Humans

Inhalation Exposure

Photometry - instrumentation

Reproducibility of Results

Details

Title: Subtitle: Characteristics of an aerosol photometer while automatically controlling chamber dilution-air flow rate
Creators: P T O'Shaughnessy - Department of Occupational and Environmental Health, University of Iowa, 100 Oakdale Campus, #180 IREH, Iowa City, IA 52242-5000, USA. patrick-oshaughnessy@uiowa.edu
D R Hemenway
Resource Type: Journal article
Publication Details: Inhalation toxicology, Vol.12(10), pp.979-996
DOI: 10.1080/08958370050138021
PMID: 10989372
ISSN: 0895-8378
eISSN: 1091-7691
Grant note: R03-OH03185-01 / NIOSH CDC HHS
Language: English
Date published: 10/2000
Academic Unit: Civil and Environmental Engineering; Occupational and Environmental Health
Record Identifier: 9984214675802771

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