So, you want to measure the shape of an object, perform a 3D surface scan or conduct surface metrology tests. Google tells us there are many measurement methods to achieve these goals. Problem is, which one’s best for you?
Object-measurement techniques can be divided into two basic categories: contact and non-contact. In the former, the object has to touch the sensor, which usually complicates the measurement process, slows it, and can possibly damage the object we examine. Moreover, if the measured object is a soft material, like rubber, textile or tissue, it can’t be measured at all. So here we’ll only discuss non-contact measurement sensors, in which the sensor and the object to be measured are separated from each other.
It all comes down to determining the precise distance between the two and moving one with respect to the other, in order to reconstruct the object’s shape. This goal can be achieved using various optical techniques, each best suited for a different type of application.