CDPH Lead Inspector/Assessor California State Practice Exam

If more than 20% of the corrected substrate values are negative, what should be done?

1. Proceed with testing

2. Check the calibration and repeat the measurements

3. Document the results without any changes

4. Ignore the negative readings

The correct answer is: Check the calibration and repeat the measurements

When a situation arises where more than 20% of the corrected substrate values are negative, it is crucial to consider the validity of those readings. Negative values can indicate issues such as equipment malfunction, improper calibration, or measurement errors. As a result, it is essential to check the calibration of the instruments used and repeat the measurements to ensure accuracy and reliability in the testing process. The importance of recalibrating the equipment and repeating the measurements lies in maintaining quality control and obtaining trustworthy data. If these negative readings are not addressed, they could lead to incorrect assessments of lead contamination, which may compromise health and safety evaluations. In contrast, ignoring negative readings or proceeding with testing without validating the initial results could lead to serious oversight in identifying hazards. Documentation without changes would not rectify the potential errors indicated by the negative values. Therefore, the focus should be on resolving the issue by ensuring that the instruments are correctly calibrated and that reliable data is obtained through repeated measurements.