If retesting is used to verify inspection quality, what is a requirement for the XRF instrument?

Using the same instrument originally during retesting to verify inspection quality is crucial for maintaining consistency and reliability in the results. The rationale behind this requirement lies in the fact that each XRF (X-ray fluorescence) instrument can have its unique calibration settings, drift over time, and variations that are consistent with its specific operational characteristics. By utilizing the same instrument, assessors can ensure that any differences found between inspections are attributable to potential changes in lead levels rather than variations in instrument performance or calibration.

Consistency in the instrument helps to uphold the integrity of the data collected. This means that reproducible measurements following the same methodology lead to reliable conclusions that can be confidently communicated to stakeholders. This approach is standard practice to ensure that the quality of the inspection process remains intact and that retesting results can be effectively compared to the original findings.