What is going on when a carpet starts rippling

What is going on when a carpet starts rippling after being installed over a concrete slab? Why would one section of carpet have a problem and not another?

Watch as Ed Wagner explains how he was able to use the Rapid RH concrete moisture test to solve exactly this kind of problem for a Wagner Meters customer.

CarpetConcreteConcrete rh testingRapid rhRelative humidity testingWagner