A New Parameter to Evaluate the Quality of Fiber Count Data of Slides with Relocatable Fields

Abstract

Asbestos reference slides with relocatable fields are effective in determining the fiber counting errors and evaluating intercounter precision and accuracy. The process is time consuming and expensive as it requires (a) the analysts to record the number and the positions of the fibers and (b) an experienced microscopist to determine the errors. A new parameter based on the discrepancies between the reported fibers and the verified fibers is being investigated for monitoring the quality of fiber counts. The discrepancies are related to the fiber counting errors. The new process requires the analysts to report only the fibers in each field examined.

Keywords:

• asbestos fibers
• microscopy
• quality control
• reference slides

ACKNOWLEDGMENT

The author would like to thank Paul A. Baron and Stanley A. Shulman for their suggestion of the project and their help in the analysis of the data. He also thanks all the laboratories and their analysts who contributed to this study.

Notes

^A The average area of a field is 0.01025 mm².

^B Relocated fields printed on to the cleared filter wedge.

^C Above PAT proficiency range.

^A Analysts #4, #8, #9, #15, #22, and #23 are excluded in the calculation.

^B Analysta #2, #9, #10, #15, #22, and #23 are excluded in the calculation.

^A Analysts #5, #20, and #23 are excluded in the calculation.

^B Analysts #7, #8, and #23 are excluded in the calculation.

^A Analysts #11and # 23 are excluded in the calculation.

^B Analysts #1, #5, #8, #9, #12, #13, and #15 are excluded in the calculation.