Bit and Fence Setup
If you work in common fractional measurements, here's a non-battery choice for your router table setups. This iGaging 2-piece Multi/Mini Gauge Set with laser engraved scales are designed for vertical or horizontal measurements such as measuring a router bit's height or its distance to the fence.
For reference, we've nicknamed the gauges "Big foot" and "Little foot"; with Big foot measuring up to 2" and Little foot up to 1" in either bit height or distance from the fence. A thumbscrew locks a center sliding scale at any fractional measurement on the scale. Then the bit is raised to meet the scale or, with the scale laying flat and against the bit, the fence moved to meet the gauge's feet.
Alternatively, there are six offsets, in 1/16" increments, ranging from 3/16" to 1/2" in the feet of each gauge that are used like setup blocks to set the fence to bit distance for straight bits.
On the Big foot scale, there are indents in the ends of the sliding scale that, when placed against the bit shank, will measure to the centerline of bits with 1/4" and 1/2" shanks.
Little Foot Gauge: 0-1" / 1/16" Scale
Big Foot Gauge: 0-2" / 1/16" and 1/32" Scales
with centerline offsets for 1/4" and 1/2" shanks
You may also want to consider the new Digital EZ-Check