XL2 800 General Testing Procedure

2 1. Good surface preparation is essential for obtaining accurate test results. All non- representative material (e.g., paint, coating, scale) must be removed prior to testing. An approximately 2-inch-square section of surface should be cleaned down to fresh or “white”/“red”/”yellow” metal using an abrasive wheel. To prevent cross contamination, wheels that have been used on one type of alloy should not be used on a different alloy type. For example, a wheel used on stainless steel should not be used on carbon steel. The area to be sampled should be wiped clean or blown with air to remove any grinding dust before testing. For the Thermo Scientific Niton XL2 Series, test times of 5 seconds on each filter (library will determine if low filter is needed) will generally give good identification of grade for most alloys. Total test time will be 5s for most samples but 10s if 2nd filter is needed. Test times of 10 seconds on each filter will generally provide accurate chemistry analysis for unknown samples. Since there are two Ranges (Main and Low), the total test time will be 20 seconds if the sample is not identified as one of the grade library samples. For the XL2 980 follow the same as above but run the light filter for at least 30 seconds.

3 General Testing Procedure The analyser will often display a correct alloy identification and accurate chemistry result before the above specified time interval. If the accuracy meets the user’s requirements, it is not necessary to measure for the full time. Longer measurements might be necessary if low concentrations of alloy elements must be determined. 2. INSTRUMENT QC Measure the supplied 1¼ Cr – ½ Mo calibration check periodically to prove analysers accuracy.

4 Undersized or non contact samples 3.1. For samples that do not fully cover the measurement aperture, increase the testing time by increasing the time in inverse proportion to the decrease in percentage of aperture covered. For example: a rod only covers ½ of the aperture, so increase the measurement time by two (e.g., from 10 to 20 seconds per filter for chemistry) The best procedure to measure undersized samples is to use the Thermo Scientific Niton portable test stand (optional), which is shielded to prevent radiation exposure to the operator. 3.3 An undersized sample may alternately be measured while lying on another material. Results may be affected by the signal coming from the underlying material itself. Use only pure aluminium, pure plastic, or clean wood and employ the Disable Al feature. Use the Tools Menu, then select Disable Al, and check the underlying surface itself to be sure no metals are present. Be sure to use the Tools Menu and select Enable Al before testing aluminium alloys.

5 Undersized or non contact samples (cont) 3.4. Non-contact sample measurements include those measured with a gap of up to a maximum of ¼ inch (~6 mm) from the Niton XL2 measurement aperture opening. Such measurements require double the exposure time. (e.g., from 5 seconds to 10 seconds for ID and from 10 to 20 seconds for chemistry) Inside pipe measurements on pipes that are less than a few feet in diameter will result in non-contact measurements. Follow recommendations in 3.2 above.