Terry, Been using one for many years to measure humidity before spraying lacquer. Have found humidity higher than 72 - 73 % could cause blushing problems and require other defensive steps. Works great...bought it at Wal-Mart ....paid approx $3.00....a great little tool....has helped me make a lot of money refinishing pianos and furniture with that ole lacquer that is dangerous, blows up, causes respiratory problems, can cause cancer and brain damage, and who knows what else. If one uses this "bad" stuff, get a Wal-Mart hygrometer. Tommy Black Decatur, Ala.
This PTG archive page provided courtesy of Moy Piano Service, LLC