Paint-chip sampling involves physically removing a small portion of painted material and sending it to a laboratory for quantitative lead analysis. This provides a direct laboratory measurement of lead concentration but causes minor damage at the sampling location.
XRF testing uses an X-ray fluorescence analyzer to evaluate lead in painted surfaces without physically removing a paint chip. This allows a trained inspector to collect many readings relatively quickly and with little or no surface damage.
Each method has advantages. Paint-chip sampling can be ideal for targeted investigations, while XRF can be particularly useful when many painted components need to be evaluated.
The appropriate method depends on the property, project scope, regulatory purpose, and number of surfaces requiring evaluation.