It's important to compensate for this distance when resetting a neck or when routing a bridge saddle slot. The gauge helps you avoid time-consuming trial-and-error.
Reset a neck without guesswork. The Top Deflection Gauge makes it easier to reset an unstrung acoustic guitar neck correctly. You can record a measurement at the bridge with the strings installed, and use a brace jack inside the guitar to restore the bridge to its exact original height when the strings are removed.
Perform bridge work more accurately. By using the gauge and a brace jack to simulate string tension, you can contour the bottom of a new bridge to more closely match the soundboard surface. When you rout the saddle slot, you'll know the bottom of the slot will be flat—that's important for good tone, and critical for undersaddle transducer pickups.
Keep your banjo sounding good: The gauge indicates banjo head deflection precisely—you can use it to record the head tension that makes your banjo sound its best.
Three holes in each end of the aluminum beam adapt the Top Deflection Gauge for a variety of soundboard widths, and a swiveling foot allows free-standing use. The dial indicator is super-accurate to .001", with adjustable zero point. The gauge measures 14" x 1" x 1/2" (355.6mm x 215.4mm x 12.7mm).