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~~ Section No. 2.2.4 Revision No. 0 Date May 1, 1977 Page 1 of 17 • 4.0 SAMPLING PROCEDURE An activity matrix for sample collection functions is presented in Table 4.1 at the end of this section. The matrix summarizes the sample collection activities and t;:= operational checks described in this section. 4.1 Installation of Filter Place the sampler in the servicing position, Figure 4.1, by raising the sampler until the filter holder is above the top level of the shelter; then rotate the unit one-eighth turn so that it hangs from the top of the filter holder. Figure 4.2 shows the normal operating configuration of the unit. During inclement weather, including high winds, the entire sampler should be removed to a protected location for servicing whenever practicable. The clean, installed filter should be protected when returning the sampler to the shelter. The use of a filter • cartridge assembly (available from General Metal Works), see Figure 4.3, permits the filter installation to be performed without requiring the entire sampler to be moved. While the sampler is removed from the shelter or before the new filter is installed, the inside surfaces of the shelter cover and the surfaces around the filter holder should be cleaned of loose particles by wiping with a clean cloth. To install a filter, remove the faceplate of the sampler by loosening the four wing nuts and swinging the bolts out- ward, see Figure 4.4. Place the filter, rough side up, on the wire screen. Center the filter on the screen so that when the faceplate is in position, the gasket will form an air- ' tight seal on the outer edge (1/2 inch) of the filter. When aligned correctly, the edges of the filter should be parallel both to the edges of the screen behind it snd,to the face- plat= gasket above it. The results of poorly aligned filters • appear as uneven white borders, Figure 4.5, around the filter.