"Tuning fork" gauge with the Gaddy tension spring opposite the anvil on the interior leg and suspended vertically DOES produce repeatable measurements. Depth of a pit cannot be "measured" but the thickness of barrel wall (including some oxides to be sure)in the pit can be with an indicator tip that will enter rather than bridge the pit. Wall thickness adjacent to the pit can also be measured. Obviously "depth" of the pit can be extrapolated: WT adjacent - WT @ pit = Depth of pit. You have to be cack-brained to believe that the indicator can't "read" the presence of a declivity/irregularity/anomaly in the barrel wall! Obviously, whether the depth of a pit can be determined depends greatly on the size of the pit and very shallow pitting is usually detected only as physical chatter or vibration in the instrument and the indicator needle. I have yet to read the New Gospel according to the Parker lads but should be interesting.
jack
Correction to above: "indicator tip" should be "anvil on interior rod." With a bearing ball of any appreciable size as the anvil, Pooch and others are right that you can't get the anvil into a very narrow pit. You certainly can get a 1/8-3/16" diameter bearing ball to drop into a larger area of pitting and you can extrapolate the depth. The idea that a "needlelike" anvil can be calibrated to a ball-end indicator tip is no more ridiculous than the opposite but I have to admit that is not how my gauge is constructed. My face is a bit red for confusing which leg of the caliper goes in the hole! One should make sure one is not waxing geriatric before waxing theoretical.
Last edited by rabbit; 09/11/12 08:51 AM. Reason: confessional
