My measurements were made with a set of long "T" shaped probes of widths from the throat i.d. up to .25" in .005" width increments, and from .26" to the bell i.d. in .01" increments. The probes are of moderately soft styrene plastic obtained from a hobby-store and inserted carefully and gently so as to be sure of an accurate reading. Depth of insertion was measured, from the top of the chanter for locations at and above the throat, and from the bell or bottom of the chanter for locations at and below the throat. Overall chanter length was measured, and measurements made from the top then converted so that all dimensions are referenced from the bottom.
My procedure is to insert a probe oriented at right angles to the finger holes until it stops under its own weight. I gently bounce the probe up and down, allowing it to fall half an inch or 10 mm, while slowly rotating the chanter to identify the deepest and the shallowest penetration depths. These are marked on the stem of the probes, which are measured later. The "T" cross-arms are also remeasured in case their widths have changed.
Click Here for a discussion on measuring chanters.
Click Here for the text file data sheet on the C# chanter.
Click Here for a medium sized 2-color graphic plot of the bore (96 Kb)