A moisture meter can support an assessment of building materials. It is not a universal pass/fail device, a contamination test or proof that an entire concealed assembly is dry.
A reading needs context
The material, meter method, location and comparison conditions affect interpretation. Different instruments or materials should not be compared as though their numbers mean the same thing. Ask what was measured and why the result matters for that part of the project.
Hidden areas remain a limitation
Access restrictions and material layers can limit what a surface check establishes. An infrared image can show temperature differences but does not, by itself, prove that the area contains water. Findings should be considered with source history and the building assessment.
Ask for an explanation, not just a number
Useful questions include which locations were checked, how progress is being followed and whether any area needs further access. Do not use an inexpensive household reading to decide that electrical hazards, contamination or suspected mold are safe.