Re: Poor Mans DRO

They are capacitive pickup devices. Imbedded in the bar the readout
rides on under the printed scale is a printed circuit board with
alternating blocks of foil spaced 0.1" apart. The electronics
interpolates the difference between them.

Moisture messes them up because it changes the capacitance of the scale.

Ken

--- In CAD_CAM_EDM_DRO@yahoogroups.com, jethrobodine
<jethrobodine@z...> wrote:

> Another related question, how do digital calipers work ? I

disassembled my foreign built calipers to see how they work and I
don't see any moving parts. If I measure something with the power off
then turn them on, the measurement is accurate which makes me think
it's not a counter. Also they are really screwed up by moisture.