Measuring device for loose circle range of coal mine tunnel

The utility model discloses a coal mine tunnel loosening circle range measuring device, which is characterized in that a power supply, a switch and a slide rheostat are connected in series by leads to form a primary circuit of a circuit, an ampere meter A, an ampere meter B, an ampere meter C and an ampere meter D are respectively connected in series by leads to be connected into the circuit to form circuit branches, one end of each branch is connected into the primary circuit of the circuit, and the other end of each branch is connected into the secondary circuit of the circuit. And the other ends of the connecting rods are respectively connected with leads of the measuring box A, the measuring box B, the measuring box C and the measuring box D. The device mainly comprises a power supply, a switch, a slide rheostat, a lead, an ampere meter, a drill hole, a test box and the like. According to the main principle, when a drill hole shrinks, a spring in a measuring box shrinks so as to generate elastic force, th