Meter reading
A meter number is a clue about the finish. It is not a map of the pipe.
Occupants buy a meter, see a high reading, and want a wall opened. Readings vary with paint, metal, and the tool. Use them to decide where to look, not what to demolish.
Take more than one reading.
Compare a dry wall in the same suite. One number without a baseline is noise.
Metal corner bead and foil backer fool some meters.
Write what the wall is made of.
A high reading plus a downstairs stain is worth a visit.
A high reading on a freshly painted, dry-feeling wall may wait for a second check.
Questions people ask
Which meter should I buy?
You do not need to. If you already have readings, bring the numbers and the locations. Investigation will still use its own checks.
Can a meter see into a pipe?
No. It reads the material it touches or the field it is designed for, not the inside of copper.