by Hannah Beckett RPT
If you want an extremely accurate measurement of key dip, try this method with your digital calipers:
First, measure key height from the keybed to the top of the key. Push the "zero" button on the calipers to clear the measurement while holding the calipers steady. Then, with a medium blow, depress the key and slide the calipers down to the top of the key while holding it depressed. Lock the calipers, and read your key dip measurement!