1. X-Ray Fluoresence Meter/Detector

2. Introduction Air monitoring data is useful for: *Assessing the health risks to the public and response workers. *Selecting personal protective equipment. *Delineating areas where protection is needed. *Determining actual or potential effects on the environment. *Selecting actions to mitigate the hazards safely and effectively.

3. X-Ray Fluoresence Meter/Detector Toxic atmosphere monitoring is done to: *identify airborne concentrations that could pose a toxic risk to response workers and the public. *evaluate the need for and type of personal protective equipment. set up work zones or areas where contaminants are or are not present. set up work zones or areas where contaminants are or are not present.

4. X-Ray Fluoresence Meter/Detector Characteristics of Air Monitoring Characteristics of Air Monitoring To be useful air monitoring instruments must be: *Portable and rugged. *Easy to operate. *Easy to operate. *Inherently safe. *Inherently safe. *Able to generate reliable and useful results. *Able to generate reliable and useful results.

5. X-Ray Fluoresence Meter/Detector The response time, sensitivity, selectivity, accuracy and precision of an instrument are important in evaluating the reliability and usefulness of the data the instrument generates. The response time, sensitivity, selectivity, accuracy and precision of an instrument are important in evaluating the reliability and usefulness of the data the instrument generates.

6. X-Ray Fluoresence Meter/Detector X-ray Fluorescence (XRF) is a nondestructive method sample is irradiated by an intense x-ray beam, which causes the emission of fluorescent x-rays emitted x-rays can either be detected using energy dispersive or wavelength dispersive detector energies or wavelengths of emitted x-rays are used to identify elements present Components present are quantified by x-ray intensity

7. X-Ray Fluoresence Meter/Detector sample can be excited by a x-ray source, by a radioisotope source, or by an electron beam XRF uses x-rays as the primacy source primary source excites sample by knocking out tightly bound electrons from the inner-shell orbital Relaxation of excited atom to ground state is accompanied by the emission of fluorescent x-rays

9. X-Ray Fluoresence Meter/Detector X-rays emitted from excited sample strike detector

10. X-Ray Fluoresence Meter/Detector Principle of Operation:

11. X-Ray Fluoresence Meter/Detector elements present in sample identified by location of energy peaks along the horizontal axis number of x-rays produced proportional to number of atoms present quantitative elemental concentrations determined from intensities of energy peak

12. X-Ray Fluoresence Meter/Detector samples can be analyzed "as is" for most qualitative analysis and quantitative analysis Some samples require sample preparation such as pelletizing or casting as fusion disk Vacuum compatibility of sample depends upon element Sample need not be conductive or insulating quantitative analysis samples should be homogeneous with flat smooth surface Qualitative and qualitative elemental information obtained from a bulk infinite thickness sample quality of results depends on calibration standards

13. References Cited http://www.xrfcorp.com/http://www.xrfcorp.com/ Accessed 05/03/01 http://www.xrfcorp.com/ http://ion.eas.asu.edu/descript_xrf.htm http://ion.eas.asu.edu/descript_xrf.htm Accessed 05/03/01 http://ion.eas.asu.edu/descript_xrf.htm NIOSH Manual of Analytical Methods (NMAM®), 4th ed. DHHS (NIOSH) Publication 94-113 (August, 1994), Cassinelli, M.E. & O'Connor, P.F. (pfo1@cdc.gov), Eds. O'Connor, P.F. (pfo1@cdc.gov)O'Connor, P.F. (pfo1@cdc.gov)

14. Bibliography DiNardi Salvatore R. (1998) The Occupational Environment-Its Evaluation and Control, AIHA, Fairfax, Virginia DiNardi Salvatore R. (1998) The Occupational Environment-Its Evaluation and Control, AIHA, Fairfax, Virginia Goetsch David L. (1999) Occupational Safety and Health for Technologists, Engineers, and Managers, Prentice Hall, Upper Saddle River, New Jersey Goetsch David L. (1999) Occupational Safety and Health for Technologists, Engineers, and Managers, Prentice Hall, Upper Saddle River, New Jersey