This technique is known as time-of-flight measurement. The inner circuitry takes advantage of this timing to calculate the distance, supplying immediate digital readouts that may be much more precise than guide methods. A few feet off is a big challenge but for my employs I think two or three mm https://cesar8pes7.wikibyby.com/1990877/top_أدوات_قياس_المسافات_بدقة_secrets