In the years since its inception, laser scanning has been applied to an increasing range of jobs that require the gathering of precise physical data from a variety of objects, spaces, and environments. However, despite the ability of laser scanning to meet these needs, meeting them with the best results typically depends on using the right type of laser scanner. Although different 3D scanners can be used to accomplish the same thing, there is always a best 3D scanner for a particular project regarding ease of use and desired data results. Below, we look at some commonly used types of laser scanners and what type scanning projects are ideal for their use.
As their name suggests, contact scanners make direct contact with the object being scanned, gathering its data points. Contact scanners are known for their incredible accuracy but are only used to scan smaller scale objects. Another limitation of contact scanners is that their probing feature, although relatively gentle, can still prove damaging to fragile objects, making contact scanners a poor choice for scanning small, irreplaceable objects, such as artifacts and delicate antiques. A typical example of the use of contact scanners is the scanning of refined clay models that will be used for product manufacturing.
Time-of-Flight scanners do not probe an object, instead beaming a laser toward objects that then refracts toward a laser rangefinder, which measures the roundtrip time of the laser from the scanner and back. The greatest advantage of time-of-flight scanners is their ability to scan large objects, such as tall buildings, from great distances away. However, their general disadvantage is that their results, though accurate, are not infinitesimally accurate. When the minute surface qualities of a large object are not essential to a scanning project, time-of-flight scanners are usually the ideal choice. A common example of the use of time-of-flight scanners is the gathering of the general data of large buildings for construction purposes.
Triangulation scanners are non-contact scanners that emit a pattern of light across an object or surface and measure the textural variations in the light’s pattern to assess the surface data of the scanning subject. The primary advantage of triangulation scanners is their ability to produce highly accurate data without probing an object, while their general disadvantage is that they cannot scan large objects from far away. There are numerous instances of triangulation scanners being used to scan large subjects, such as the Mount Rushmore sculpture, which was scanned for restoration purposes with triangulation scanners in May 2010. In such cases, scanning sites are identified across the surface of the subject and scanning professionals use safety gear to arrive at the sites.