The sensors of the LD90-3 series are based on the well-proven principle of time-of-flight measurement of short laser pulses. They can be operated with practically any target surface, i.e. "reflectorless" up to many hundred meters, and up to more than 1000 m with reflecting foil or retroreflectors.
The distance and level meter LD90-3-GF is a measuring system consisting of an optical head and a separate electronics box connected by a duplex glass-fiber cable. The optical head can be operated in exposed environments (like high temperature areas), whereas the electronics box can be remotely installed in a protected area.
The RIEGL LD90-4 is an economically priced, high reliability distance sensor for industrial use "reflectorless" or with retroreflecting targets. The implemented "High Penetration" technology allows its use even under conditions of bad visibility, e.g. rain, dust, fog etc.