Optical design and measurements
The linear velocity of the beam spot on scanning line is an important parameter of the laser micrometer. It is shown in Fig. 4 for object size from 3–13 mm with different RPMs. The linear velocity of the scanning line is the velocity of the spot throughout the scan line. It is measured by dividing the object size by the time taken by the line to cross the object. In other words it is an inverse of the slope of the curve in Fig. 3. This is calculated for several values of RPM. It is shown that for RPM values between 2000 and 8000 the velocity of the line is less than 0.87% variation for object size 3–13 mm.