A New High-Speed Method For Confirming The Quality Of L X-Ray Lead Paint Measurements In The Field

摘要

In L x-ray measurement of lead in paint, overlying layers of nonlead paint attenuate the low energy L x-rays, reducing the signal. L x-ray-based algorithms can correct for this reduction of signal and maintain the accuracy of the L x-ray method over a wide range of conditions. But in extreme and generally rare cases, the overlying paint films are so thickn and absorptive as to reduce the L x-ray signal to below the level at which dtection of deeply buried lead is reliable. A new method, also an x-ray-based algorithm, ocmblements the correction algorithm by instantaneosly confirming that the paint coating is not too thick and absorptive to allow reliable L x-ray detection and quantitation of buried lead. In the few cases where the new method does not confirm the L x-ray measurement, the instrument operator may choose alternative methods for confirmation, such as K x-ray, intrustive L x-ray, chemical spot test, or laboratory sampling. With instant confirmation, L x-ray technology achieves reliable, precise, accurate, high-sensitivity, high-speed (3 to 20 seconds), and substrate-independent non-destructive field measurement of lead in the great majority of "real world" paint samples.