Telah dilakukan penelitian untuk mengukur bentuk dan dimensi obyek dengan teknik moiré. Pengukuran dilakukan dengan cara mengamati spasi moiré akibat interaksi antara kisi dan bayangan kisi pada permukaan obyek akibat sorotan lampu proyektor dengan kamera CCD (Charge Coupled Device). Selanjutnya data yang diperoleh diolah secara offline. Dengan melakukan pergeseran fasa berturut-turut sebesar π/2, π dan 3π/2 terhadap obyek bola pingpong yang berjarak 48 cm dari sumber cahaya dan kamera CCD, jarak antara sumber cahaya dan kamera CCD 13,5 cm serta spasi kisi 0,5 mm, diperoleh bahwa bentuk permukaan cembung dapat diidentifikasi dengan resolusi sebesar 0,24 mm. Juga ditunjukkan bahwa perbedaan terbesar antar hasil pengukuran teknik moiré dengan pengukuran secara kontak CMM (Coordinate Measuring Machine) sebesar 0,3 mm.
The Use of 2D Plastic Grating for Surface Profile and Dimension Manufacture Product Measurements by Using NDT Moiré Technique. Research of measuring the shape and dimension of object using the moiré technique have been done. Measurement have been made by observing the moiré space as a result of interaction between grating and its shadow casted on the object?s surface caused by the projector lamp with CCD camera. The acquired data was further processed by way of off-line. By successive phase shifts that is π/2, π dan 3π/2 towards the table tennis ball at the distance of 48 cm from the light source and CCD camera, with the distance between CCD Camera and light source 13,5 cm and grating space 0,5 mm. It was obtained that convex shape can be identified by resolution of 0,24 mm. It was also shown that the biggest difference between the results of using moiré technique and the use of CMM contact measurements (Coordinate Measuring Machine) was 0,3 mm. |
