Instruments de mesure électronique de distance

Electronic Distance Measuring Instruments (EDM) measure distances precisely using either light waves or microwave signals. 

Both methods send an electromagnetic signal from the instrument to a reflector at the target point and back to the device. 

The time taken for the signal’s return allows the EDM to calculate the distance accurately.

Instruments using light-based signals are generally effective for shorter, clear-line distances. 

These instruments typically use infrared or laser light, which ensures high accuracy when environmental conditions are clear. 

On the other hand, microwave-based EDMs are well-suited to longer distances and can operate effectively in challenging weather since microwaves penetrate obstacles like fog and rain.

Within these signal types, EDMs measure distances using Phase Shift or Timed-Pulse methods. 

Phase Shift EDMs measure the phase difference between the outgoing and incoming signals, achieving high precision over short distances. 

Timed-pulse EDMs measure the time it takes for the signal to travel to the target and return, allowing for accurate long-range measurements. 

These approaches provide adaptability across various surveying tasks, enhancing accuracy and efficiency in distance measurement.