You might not use a moisture meter often, but it's very handy to have your own once the need arises. No need to look for a power outlet, since it runs on batteries. Just get at it!
From Amazon
Laserliner rollpilot D12
Conrad Electronic
Laserliner Roll-Pilot D12 Perambulator 9999.99 m
ITS
Laserliner 075.006A RollPilot D12 Foldable Digital Measuring Wheel 1.0M