A Novel System for Analysis of Surface Profiles from 3-D Components Using the Dickinson Rotating Ring Contact Profiler

2.1. Surface Profilometer

The Taylor Hobson instrument employs the movement of a 90^o conical diamond stylus with a spherical tip in the range of 6mm which is carried at one end of a beam pivoted at the fulcrum on knife edges. The remote end carries an armature which moves between a pair of coils altering their relative inductance. Special gauges are employed to amplify the signal increasing the resolution ratio from 1000:1 to 64000:1 allowing a 0.6nm resolution to be reached for a range of 0.03 mm in the z-direction with a maximum nominal measuring range of 0.8mm. The instrument has a length interval of 120 mm/0.1 mm (x_max/x_min). The data sampling interval is 0.25 mm for traverse length to 30 mm and 1 mm for length over 30 mm. The instrument is controlled by Ultra software incorporating calibration and measurement functions. For the roundness of a surface device, like the Talyrond has been employed. This instrument provides the operator with a spindle provided by the company. This allows for the precision profile testing having a large accuracy of less than 0.02um radial axial. The device also has a coning error of 0.0003um/mm (Tan & Ripin, 2011). The data points gathered from the instrument sample at an extremely high level of 18000 points. However the problem still posses with this device how can the piston ring be mounted and profile in its circular profile. Each roundness profilometer offer the same problem of “how can the piston ring be mounted into a position where the contact face can be checked.”