DEVELOPMENT OF AN INERTIAL PROFILOMETER

The information in this report covers the design, fabrication and testing of an inertial profilometer system, developed for use on the FRA Test Cars. The profilometer is used to measure rail profile at high speeds, relative to an inertial reference. Design details and analysis of the profilometer are covered, and comparisons are made between profilometer measurements, mid-chord measurements, and manual measurements made with stringline and roll-ordinator devices, to show the relative accuracy of the profilometer measurements. The inertial profilometer offers several advantages over the currently-used mid-chord syystem. Accuracy of the profilometer has proven to be quite good. Operation of the profilometer is not degraded by inclement weather, and system components are not subject to damage by protruding objects in close proximity to the rail being measured.