Hi All, Just another bit of data for my quest for a humdity *fudge* factor when recomending tunings. The piano this time was an Everett 42 console with metal back posts (serial # 219774). It is equipped with a damppchaser system and plastic back cover. The piano was last tuned February 15, 2000. At that time the humidity control system was unplugged and empty of water. The humidity was a scant 18%. As the piano was to be used for a function that day where A440 was requested I pitch corrected between 24 and 108 cents, warned them to not plug in the unit til after the performance and booked a tuning for June 1, to take care of the instabilities that would have developed with the return of the control system. I arrived to find the piano had drifted 18 cents sharp. If we assume the control system is set for 42% the change in humidity was 24% from the last tuning. This give a fudge factor of .75 cents per 1 percentage change in humidity. These results happen to be exactly the same as the previous instance that I reported on where the piano was unplugged and the instrument had drifted flat. I do hope that some one else will be able confirm this. But I think so far we may suggest that pitch drop in well made console pianos is about .75 cents for each percentile change in humidity, whether that percentage change is up or down. If any one has any data to add *please* post to the list or to me personally at drose@dlcwest.com 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
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