A NEAR REAL-TIME BERYLLIUM MONITOR WITH CAM AND WIPE ANALYSIS CAPABILITIES
Science & Engineering Associates, Inc. (SEA), under contract No. DE-AC26-00NT40768, was tasked by the US Department of Energy--National Energy Technology Laboratory to develop and test a near real-time beryllium monitor for airborne and surface measurements. Recent public awareness of the health risks associated with exposure to beryllium has underscored the need for better, faster beryllium monitoring capabilities within the DOE. A near real-time beryllium monitor will offer significant improvements over the baseline monitoring technology currently in use. Whereas the baseline technology relies upon collecting an air sample on a filter and the subsequent analysis of the filter by an analytical laboratory, this effort developed a monitor that offers near real-time measurement results while work is in progress. Since the baseline typically only offers after-the-fact documentation of exposure levels, the near real-time capability provides a significant increase in worker protection. The beryllium monitor developed utilizes laser induced breakdown spectroscopy, or LIBS as the fundamental measurement technology. LIBS has been used in a variety of laboratory and field based instrumentation to provide real-time, and near-real-time elemental analysis capabilities. LIBS is an analytical technique where a pulsed high energy laser beam is focused to a point on the sample to be interrogated. The high energy density produces a small high temperature plasma plume, sometimes called a spark. The conditions within this plasma plume result in the constituent atoms becoming excited and emitting their characteristic optical emissions. The emission light is collected and routed to an optical spectrometer for quantitative spectral analysis. Each element has optical emissions, or lines, of a specific wavelength that can be used to uniquely identify that element. In this application, the intensity of the beryllium emission is used to provide a quantitative measure of the abundance of the element in the sample. The monitor can be operated in one of two modes, as a continuous air monitor (CAM), or as a wipe monitor. In its CAM mode, the monitor collects an air sample for a user programmable sampling time on a conventional mixed cellulose ester (MCE) filter. The monitor can also be used in a wipe analysis mode, where the user can load up to 60 previously collected wipe samples, typically obtained on 47 mm filter media, into disposable filter cassettes. Under this effort, a beryllium monitor was designed, fabricated and tested. During laboratory testing, the monitor's measurement performance met the stated measurement objectives at the outset of the project. A typical minimum detectable beryllium mass for the monitor is below the 0.2 mg/m{sup 3} goal of the project. Field-testing of the monitor show it to exhibit extremely good sensitivity to very low levels of beryllium. On a per spark basis, the monitor has been shown to be capable of detecting a few tens of picograms of beryllium. At the culmination of the project, the beryllium CAM unit was delivered to the U.S. DOE-Rocky Flats Environmental Management Site where it is undergoing additional on-site evaluations.
- Research Organization:
- Science & Engineering Associates, Inc. (US)
- Sponsoring Organization:
- (US)
- DOE Contract Number:
- AC26-00NT40768
- OSTI ID:
- 836182
- Resource Relation:
- Other Information: PBD: 1 Dec 2002
- Country of Publication:
- United States
- Language:
- English
Similar Records
On-Line Measurements of Beryllium, Chromium, and Mercury by Using Aerosol Beam Focused Laser-Induced Plasma Spectrometer and Time-Integrated Filter Sampling Reference Method
On-Line Measurement of Beryllium, Chromium, and Mercury by Using Aerosol Beam Focused Laser-Induced Plasma Spectrometer and TIme-Integrated Filter Sampling and Reference Method