An adjustable sensitivity shadow moiré technique for surface morphology measurement

Abstract

In this paper, an adjustable sensitivity of measurement system based on the shadow moiré technique is proposed. In this measurement system, an adjusting mechanism can control the illumination angle to change the moiré contour intervals and vary the moiré fringe spacing correspondingly. In the experiments of this paper, the suitable density of the moiré fringe can effectively reduce the influence of the noise of the image and keep adequate accuracy of the measurement system simultaneously. An accurate evaluation method for determining the sensitivity is proposed for the measurement system. By using the phase stepping technique, the proposed measurement system can analyse the fringe pattern and measure the surface profile accurately. Some samples are measured to validate the feasibility of the proposed system, and the experimental results verify the effectiveness of the developed three-dimensional profilometer to be applied for various microscale measurement applications.