The LM-SD is a laser based distance measurement tool used to measure distances from 0.2m to more than 100m with pinpoint accuracy. A given target can be clearly identified with the help of a red laser sighting point. The usable range of the sensor is dependent upon target physical properties.
The range finder is based on comparative phase measurement. It emits high-frequency modulated light which is diffusely reflected from the target and returns to the instrument with a certain phase shift compared with the emitted signal. The distance can then be determined with millimeter accuracy from the amount of this phase shift.