THE ALLOWABLE SPACING FOR LATTICE DATA SAMPLING BY A ROUND STYLUS TIPAND AN ASSESSMENT OF THE ENVELOPE SURFACE

This paper deals with surface waviness assessment by a commercial thre e-dimensional stylus instrument. To measure macroscopic waviness curve on an engineering surface, it was proposed to use a round stylus tip of relatively large radius. Developed in this paper, is a method to ob tain the appropriate stylus tip radius in accordance with the sample s urface texture and the corresponding discrete spacing for lattice data sampling. On condition that any two adjacent height data points are w ell-correlated, the statistical mean height and the overall deviation of the 3-D undulation summit height are also presented for a functiona l evaluation of waviness curves or envelope surface.