NYC-WTC_000219925

NYC 9/11 Public Portal Document

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sion) Duplicate analysis 1 per 100 samples 2 X Poisson std. (measure of repro­ Dev. ducibility) Known samples of Training and for 100% typical materials comparisons (working with unknowns standards) Analysis of NBS SRM 1 per analyst per 1.5 X Poisson Std. 1876 and/or RM year Dev. 8410 (measure of accuracy and comparability) Data entry review Each sample 95% (data validation and measure of completeness) Record and verify 1 per 5 samples 80% accuracy ID electron diffr action pattern of structure Calculations and Hand calculation of 1 per 100 samples 85% data reduction automated data reduction procedure or independent recal culation of hand- calculated data

1. When the samples arrive at the laboratory, check the samples and documentation for completeness and requirements before initiating the analysis.

2. Check all laboratory reagents and supplies for acceptable asbestos background levels.

3. Conduct all sample preparation in a clean room environment monitored by laboratory blanks. Testing with blanks must also be done after cleaning or servicing the room.

4. Prepare multiple grids of each sample.

5. Provide laboratory blanks with each sample batch. Maintain a cumulative average of these results. If there are more than 53 fibers/mm<2> per 10 200-mesh grid openings, the system must be checked for possible sources of contamination.

6. Perform a system check on the transmission electron microscope daily.

7. Make periodic performance checks of magnification, electron diffraction and energy dispersive X-ray systems as set forth in Table III and under Unit II.I.

8. Ensure qualified operator performance by evaluation of replicate analysis and standard

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