However, you’d still need a ruler, pencil,
and paper to preserve the context of the
picture. Unless your camera could take 3D images,
that is.
Laser scanners, such as Photon 80 and Photon
20 from Faro Technologies, do just that. Using
a near-infrared laser that is safe and invisible
and a mirror spinning at up to 2,880 rpm, the
scanner rasters the beam over the scene being
documented. An avalanche photodiode (ADP)
detects the reflected beam, and an onboard PC
correlates horizontal and vertical mirror angles
with the beam’s phase shift to calculate distances
from the camera to points on the target.
Repeat this at a up to 120,000 points/sec and
a 3D point cloud with up to 700 million pixels
gets stored in the scanner’s 80-Gbyte hard
drive. Ethernet and WLAN connections enable
remote data storage, viewing, and scanner
control. An optional add-on sends images in
real time to laptops, cell phones, PDAs, or any
wireless device.
Users can import the point
cloud into CAD programs for to
build a component library, reverse
engineer a device, or compare
dimensions.
For the Photon line, Faro
switched from a photomultiplier
to an APD and installed a bigger
lens to capture more light. This improves
range and boosts detection
of less-reflective objects, those in
shadows, and surfaces at oblique
angles. Software upgrades edit out
noise in the point cloud.
Mechanical and encoder hardware
place points to within ±2 mm
when measured from 25 m. Maximum
measurement distance is 2
m for the Photon 20 and 76 m for
the Photon 80, farther than older
scanners. Both units can scan a
360° horizontal field of view and
320° vertically. An optional camera
lends realistic color to scans.
Heat generated by the mechanical
and computing components is
dissipated by the housings’ ribbed
design. A carrying handle, a builtin
connector for tripod mounting,
and an optional 6-hr battery makes
the 35-lb devices suitable for construction-
site and shop-floor work.
Make Contact
Faro Technologies Inc.
faro.com