** XRF analysis **
X-ray fluorescence analysis has been used for measurement of lead in paint for more than a decade. The early systems provided a nondestructive alternative technology to laboratory-based technologies, but were somewhat time consuming and often led to inconclusive results. The procedure required manual substrate correction, multiple measurements, operator’s discretion in validating a measurement due to interfering elements and laboratory analysis of inconclusive samples.
Only if you are using the newer RMD LPA-1 system, that has been developed based on X-ray fluorescence technology does it address all of the drawbacks to the older systems. This new system uses a carefully designed and controlled geometry and modern microprocessor technology to automatically provide a rapid quantitative measurement of lead in paint with a 95% confidence level.
Tech is not always the answer. The commenters example of using XRF rather than swab is a perfect example. Swabs tested at a reputable lab will always come up with correct results, require minimal training on the part of the tester, and are very inexpensive for both the consumer and the tester. Xrf equipment is neither inexpensive for either nor does it come close to being accurate most of the time for this purpose without extensive training, controlled conditions for testing and equipment calibration.