Thermo Scientific NITON XL3t 500 User Manual page 55

Environmental
Screening Techniques
Thermo Scientific
Because you are testing through a bag, test results will tend to be lower
than test results obtained from direct analysis. This effect will vary
depending on the element analyzed and the thickness and composition of
the cloth through which the sample is tested. Bagged samples can be
retested and/or be further prepared and then retested, allowing samples of
particular interest to be more accurately analyzed.
Environmental testing is used to assure that the site stays within the
environmental guidelines of the government overseeing the operation.
Environmental testing can give warning of possible environmental guideline
violations, giving the site ownership opportunity to fix the problem before
regulatory processes intervene. Areas downwind and downstream from the
site should be patricularlyclosely moitored for higher than normal levels of
metals.
Use direct measurement when you need to determine whether an element is
present (rather than in accurately measuring how much is present). Use
preliminary direct measurements to survey a site quickly even if you intend
to take samples
WARNING! When taking samples from a site where toxic chemicals may be
present, always use gloves and respiration equipment for your own
protection.
1. Select a measurement site, and clear away any surface debris and
vegetation.
Note Valid results will depend on a sufficient and appropriate selection of
sites to sample. Lead-in-soil from paint, for instance, will usually be
concentrated within a few feet of the painted structure.
2. Choose an area to test where the measurement window of the
analyzer will be flush with the test media. Position the nose
against the surface to be analyzed and initiate a reading by
squeezing the shutter release, and firmly pressing the instrument
flat against the surface.
3. After the test, inspect the nose of the instrument for
contamination, which may affect future analysis. If the nose
appears to be soiled, clean it with a soft cloth or tissue.
Analysis of Unprepared Samples – In Situ
NITON XL3 Analyzer User's Guide 1-41