The gains in performance, coupled with the laser rangefinder's rich set of features, make it an ideal instrument for many surveyors, mappers and other geomatics professionals. Pointing systems, which began with sighting telescopes mounted on top of the units, now also include heads-up displays (HUDs), markers in the field of view of binocular systems and visible laser dots. Development of this technology is also occurring in the way of software. Software functions run the gamut from calculation of coordinates to intersections to determining azimuth and distance between two observed points. Other software routines found in this batch include various options to determine height, coordinates, vertical distances between the observer's position and the point being observed, or between two observed points, settings to prevent false measurements by eliminating the distance ranges at which clutter along the line of sight may return a spurious signal, and inversing between points. Some have internal data collection capabilities.
The IP Rating SystemThe IP rating system is becoming more common to define resistance to dust and moisture intrusion. IP stands for ingress protection. The first digit of the number refers to dust protection and the second relates to protection from water.
In the laser rangefinder survey IP numbers vary from a low of 54 to a high of 67. The IP numbers by themselves do not complete the definition. Details about conditions of time, pressure and depth must still be stated by the manufacturer for the rating to be meaningful. The (paraphrased) definitions for the included numbers are as follows:
Dust (first digit)
- 5 Dust protected-not totally impervious to dust, but does not enter in sufficient quantity to interfere with satisfactory operation of the equipment
- 6 Dust-tight-no dust enters
Water (second digit)
- 4 Splashing water protection-water splashed from any direction will have no harmful effect
- 5 Water jet protection-water emitted from a nozzle in any direction towards the enclosure will have no harmful effect
- 6 Heavy seas protection-water from heavy seas or powerful jets in any direction towards the enclosure shall not enter the enclosure in harmful quantities
- 7 Immersion protection-water ingress in a harmful quantity shall not be possible while the enclosure is immersed under the defined pressure and time conditions