The utility model discloses an around membrane machine with gauge length function, first skidding lies in around the top of membrane mechanism, and rotatable installing on the support, and separate alternate with first skidding of second skidding sets up, and rotatable installing on the support, and the heating pipe lies in the below of second skidding and vertical being fixed in on the support, the cooling tank is located the below of heating pipe, and what the third skidding was rotatable installs on the inner wall of cooling tank, in this way, the over twisting spring is led to to the one end of positive plate, and elastic articulate on the support and the electricity is connected in pulse signal record appearance, top and electricity that the negative pole piece is fixed in the positive plate are connected in pulse signal record appearance, positive plate and the contact of negative pole piece and form pulse current and import pulse signal into and write down the appearance when the positive plate is in normal condition, it drives protruding piece (15) and rotates to the positive plate on to trackslip the measured time when the first round, make the positive plate in the negative pole part even, pulse current disappears. Should be around the length of membrane machine measurable quantity stranded conductor.