The Sanderson Accu-Fork
We've tried to improve upon the old reliable tuning fork with the help of some electronic circuitry. The tuning fork may still be more difficult to drop and break, but the SAF II has its advantages, too.
Temperature has almost no effect on the SAF II, in 40 degrees the tuning fork changes about five cents, while the SAF II changes less than one third of a cent. The guaranteed accuracy of the SAF II is superior at room temperature, being within one half a cent at A-440.
And try to change the pitch of a tuning fork to measure the flatness of a piano! With the fifty cents flat or sharp scale of the SAF II, it is easy to measure flatness and then overpull pitch to cancel the anticipated drop.
The Accu-Fork has been redesigned for easier use with push button on-off control for the four notes, A4, A#4, B4 and C5, and a cents scale that is about twice as long as it used to be. It still has same size and weight and the same pleasant overtone-rich oboe-like tone quality. A touch-scale is available for blind tuners at no extra charge.