Which part of a total station is responsible for emitting infrared light?

The electronic distance meter (EDM) is responsible for emitting infrared light in a total station. This component plays a crucial role in measuring distances by sending out a beam of infrared light towards a reflector positioned at the target location. The EDM then measures the time it takes for the light to travel to the reflector and back. This time, combined with the speed of light, allows for precise calculations of distance, which is essential in surveying and civil engineering applications.

The EDM's technology forms the basis for many modern surveying practices, offering accuracy and efficiency over traditional methods. The other parts mentioned, such as the theodolite, reflector, and leveling instrument, have different functions and do not emit infrared light. The theodolite is used for measuring angles, the reflector serves as a target for the EDM’s light, and the leveling instrument assists with achieving horizontal alignment but does not contribute to distance measurement with infrared emissions.