Engineering Laser Scanning: What Types of Scanners Do Engineers Use?

Introduced in the late 1990's, laser scanners were an instant hit with the engineering industry. Unlike previous data surveying methods that were time consuming, costly, and yielded less than precise data, 3D laser scanning was fast, affordable, and extremely accurate. Compared to scanning, older surveying methods are cost prohibitive for two reasons: they require more involvement of the surveyor, and they require the production of 2D and 3D drawings. Scanning, on the other hand, requires minimal involvement of the surveyor and produces computer data models that can be manipulated as the client sees fit, eliminating the need for more surveying to produce new perspectives on already surveyed subjects. Read more at 3d laser scanning.
While some firms buy their own scanning equipment, others outsource their needs to a scanning service that specializes in engineering laser scanning. In most cases, the decision to scan in house or outsource is determined by whether a company could save more by outsourcing than buying scanning equipment, which could easily cost six figures. But, regardless of a firm's decision, it typically uses one or more of three types of scanners to carry out data gathering for such endeavors as: clash control for piping, 3D topographical site scanning, building and site modeling, 3D animation, BIM modeling, and verification of construction adherence to engineering.
Engineering Laser Scanning: Three Types of Commonly Used Scanners
In engineering, scan data is initially used to conceptualize and model designs. But it ultimately facilitates the linkage of information between architects and construction companies. Depending on a firm's focus, it may use all of the following scanner types for both purposes: contact, time-of-flight, and triangulation.
1. Contact Scanner
As their name suggests, contact models gather the data of a survey subject by actually contacting it, using sensitive probes that are capable of gathering extremely accurate data. The upside of contact models is their extreme accuracy. Their downside is that they can't scan larger objects and their probing feature could damage delicate objects.
2. Tim-of-Flight Scanner
Time-of-flight models are the antithesis of contact scanners: they shoot a laser at larger, distant survey subjects, using a special rangefinder to measure its round trip time from the scanner to the subject and back. The upside of time-of-flight scanning is that it can gather the data of expansive subjects, such as large buildings, natural environments, and areas of topography. Its downside is that it offers detailed but not infinitesimally detailed data, although no firm would use it when the latter is required.
3. Triangulation Scanner
Triangulation models emit a pattern of light across the survey subject, using a special camera to record its deviations due to the subject's surface qualities. Their upside is their extreme accuracy and their ability to be mounted at various stations on a large scanning subject to record its entire data set. When used within their capacity, they have no foreseeable downside.