CDPH Lead Inspector/Assessor California State Practice Exam

How many XRF readings are needed for substrate correction?

1. 4

2. 6

3. 8

4. 10

The correct answer is: 6

The requirement for six XRF (X-ray fluorescence) readings for substrate correction is based on industry standards that aim to ensure accuracy and reliability in lead hazard assessments. When conducting XRF testing, a minimum of six readings allows for a comprehensive evaluation of the lead content, particularly when accounting for variations in substrate materials that may affect the measurements. By obtaining six readings, any potential anomalies can be averaged out, leading to a more precise understanding of the overall lead presence in the specific area being tested. This number is sufficient to provide a solid statistical foundation, minimizing the influence of any outlier readings that could skew the results. This practice is essential for ensuring that the data collected is representative of the true lead levels in the substrate material being assessed. In summary, the standard of six readings is established to maintain accuracy, reliability, and integrity in lead inspectors' assessments.