CDPH Lead Inspector/Assessor California State Practice Exam

What does the substrate correction procedure involve?

1. Taking only one XRF reading

2. Using a single substrate type

3. Averaging six readings for each substrate

4. Shifting the reading location each time

The correct answer is: Averaging six readings for each substrate

The substrate correction procedure involves averaging six readings for each substrate to ensure a reliable and accurate assessment of lead levels. This method is essential because the presence of different underlying materials (substrates) can affect the readings obtained from an X-Ray Fluorescence (XRF) device. By taking multiple readings and averaging them, inspectors can account for variability and obtain a more accurate measurement that reflects the true lead content of the surface being tested. This practice helps mitigate the potential impact of anomalies or variations caused by the substrate and provides a better representation of lead exposure risks. Using a single substrate type, taking only one XRF reading, or shifting the reading location each time would not provide the comprehensive data necessary to accurately assess lead levels. These approaches could overlook critical variances and lead to misleading conclusions about the presence of lead hazards. Therefore, averaging multiple readings across a consistent substrate type is pivotal for the reliability of lead assessments in various environments.