Hi Terry, The strings don't have much mass and metal contracts as it is cooled. It takes only a few seconds to test this. Put a piece of ice in a plastic bag and touch it to a freshy tuned unison. Leave it there for 30 seconds. Now listen or check with a VTD. The plate being much more massive takes longer to adjust. A phenominone know as thermal drag. At 04:43 PM 3/29/00 -0500, you wrote: >Now why would turning on the AC make a piano go sharp? The cooler temp. >would make the plate and case contract (albeit very slightly), thus lowering >pitch, and the lower humidity (because any properly operating AC unit will >remove water from the air, thus lowering relative humidity) would tend to >make the soundboard contract, again lowering the pitch. Why in the world >would it go sharp? > >Terry Farrell Regards, Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T. Tuner for the Saskatchewan Centre of the Arts drose@dlcwest.com http://donrose.htmlplanet.com/ 3004 Grant Rd. REGINA, SK S4S 5G7 306-352-3620 or 1-888-29t-uner
This PTG archive page provided courtesy of Moy Piano Service, LLC