What is beam divergence, and why can readings mix different objects?
A laser beam does not stay indefinitely narrow over a long distance. The illuminated area grows. This spreading is called beam divergence. The area may also grow differently in width and height. The aiming mark visible on the display therefore does not necessarily show the laser spot’s actual size and shape.
A laser beam does not stay indefinitely narrow over a long distance. The illuminated area grows. This spreading is called beam divergence. The area may also grow differently in width and height. The aiming mark visible on the display therefore does not necessarily show the laser spot’s actual size and shape.
When light hits several surfaces, several signals may return. Think of a branch in front of the intended object and a wall behind it. The instrument has to decide which signal to display. Names such as first-target, distant-target or best-target mode describe different selection principles. Their precise operation may vary between instruments.
A repeatedly displayed number therefore does not automatically prove that the intended object was measured. Beam shape and handling of uncertain signals also matter when comparing instruments. If an instrument displays no value, that can be a sensible response to an ambiguous measurement. It does not necessarily mean the instrument is faulty.