Development and characterization of a new instrument for the traceable measurement of areal surface texture

Abstract

Modern manufacturing industry is beginning to benefit greatly from the ability to control the three-dimensional, or areal, structure of a surface. To underpin areal surface manufacturing, a traceable measurement infrastructure is required. In this paper, the development of a new traceable instrument for the measurement of areal surface texture is presented. The instrument uses a two-axis coplanar air-bearing slideway to move the measured surface beneath a stylus probe. The motion of the slideway is measured using linear and angular interferometers. The key to the new instrument is a novel probing system incorporating a cylindrical air-bearing guideway and an electromagnetic system to maintain a constant stylus force on the surface. The deflection of the stylus is measured using a differential plane mirror interferometer thereby minimizing the effect of any error motion in the metrology frame. The uncertainties of the instrument are calculated using a Monte Carlo approach and are evaluated to be 5 nm in the z axis and 16 nm in the x and y axes (all at k = 2). The results are given for the instrument and are compared to results from a traceable profile measuring instrument and a coherence scanning interferometer.

Calibration and verification of areal surface texture measuring instruments

“…NPL and PTB have both developed primary stylus instruments, which use xy air-bearing slideways to move the object being measured, have laser interferometers which monitor the motion of the slideways, and use probes with air-bearing motion control and electromagnetic stylus force control [113,175]. Fig.…”

“…Cross-sectional representation of the probing system on the NPL primary areal instrument: (a) conventional diamond stylus, (b) Zerodur rod, (c) mirror for interferometer, (d) air-bearing piston, (e) end of the air -bearing piston (part of the anti-twisting device), (f) spacer, (g) toroidal permanent magnet, (h) aspheric lens, (i) air-bearing, (j) anti-twisting device, (k) coaxial coils and (l) heat exchanger[113].…”

Displacement Measurement

“…With this method, fringe subdivisions of λ/1000 are common, giving sub-nanometre resolutions for both heterodyne and homodyne systems. There are many homodyne and heterodyne interferometers commercially available, and the realisation of subnanometre accuracies in a practical setup is an active area of research [8,9]. Many of the modern advances in high-accuracy interferometry come from the community searching for the effects of gravitational waves [10].…”

“…In both cases, periodic errors with amplitudes of less than 0.1 nm were measured once a Heydemann correction (see Section 5.3.8.5) had been applied. More recently, a comparison of the performance of the next generation of optical interferometers was undertaken using X-ray interferometry [8]. X-ray interferometry can also be used to calibrate the characteristics of translation stages in two orthogonal axes [105] and to measure nanoradian angles [106].…”

Magnetic Material Characterization Using an Inverse Problem Approach

“…This sCRB offers the lower bound of the error within a rather small computational time compared to the well-know time-demanding techniques such as Monte Carlo simulations applied in e.g. (Leach et al, 2009), stochastic finite element method (Beck & Woodbury, 1998), polynomial chaos decomposition (Gaignaire et al, 2010).…”