I use a small piece of stiff wire about 3" long bent in one place off center at whatever you determine to be a good angle. I've used 17 degrees in the past, but whatever you prefer and depending on the section. With action removed this piece of wire can be held with bend against the bar between unisons and one side along speaking length to compare your known angle with that existing on the piano. Some simple adjustment to the gauge wire then, can also give you a fairly close measurement. good luck, Dennis Johnson St. Olaf College
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