MARKING GAUGE AND BRANCH CONSTRUCTING METHOD USING MARKING GAUGE

PROBLEM TO BE SOLVED: To enhance work from formation of an opening 16 to dimension measurement. SOLUTION: When opening 16 is formed in the pipe wall of a cable protecting pipe 12, the body 20 of a marking gauge 10 is put on a specified position of the external surface of the protecting pipe 12, and a marking line for the opening 16 is drawn along the internal circumference of a hole 22 using a felt pen 26 for example. After the marking gauge 10 is removed, an opening 16 is formed by cutting the pipe wall off with a drill, cutter, or saw, etc., along the mark line. After that, the hole 22 is caused to correspond to the opening 16, the marking gauge 10 is put again on the external surface of the protecting pipe 12, and the dimensions of the opening 16 are measured with graduations 24. Along with it, the opening 16 and the marking-off gauge 10 are photographed. Since the body 20 is transparent, there is no fear of the opening 16 becoming invisible, even if the marking gauge is put on the external surface of the protecting pipe 12.