Height measuring device

The utility model discloses a height measuring device, including act as go -between, inner tube, outer tube, transverse bar, test position, steel band, the test position includes: upper cover, lower cover, PCB circuit board, transcoding wheel, zero point reset switch, CPU and two opto -couplers, PCB circuit board is fixed and is covered under, and reset switch and opto -coupler were established on PCB circuit board CPU, zero point, and the receiving terminal of reset switch and opto -coupler was connected with CPU zero point, the signal of an opto -coupler is used as the judgement rotation direction as computed range, the signal of two opto -couplers, and the transcoding wheel lian zaishang cover, the outer tube is connected with the test position, and the inner tube is established in the outer tube, and the bottom of inner tube is connected with the one end of acting as go -between, and elastic bulge portion and reset switch alignment at zero point are established to the bottom of inner tube, and the transverse bar links the top at the inner tube, the other end of acting as go -between is around outside the transcoding wheel, and the steel band is coiled inboardly at the transcoding wheel, and when the inner tube was tensile, the drive transcoding wheel of acting as go -between rotated, and during the shrink, the steel band drives the rotation of transcoding wheel and acts as go -between in order to draw in. The utility model discloses can accurate measurement height.