- nominal diameter of a controlled part (pipe), mm 100; 120; 122; 152; 155
- length of a controlled part, mm up to 8000
- deviation of the measured diameter from nominal rate, mm -0,2…+0,8
- least significant digit of the diameter value, mm 0,001
- error of measurement of a diameter, mm, no more than 0,.015
- measuring resolution of the axial movement of the device, mm 10
- error of determination of axial coordinate of the measured section with the length of a part of 6000 mm, mm, no more than 20
- speed of measurements, mm/s, up to 90
The device consists of a measuring unit and a recording units connected to each other by a cable. Following adjusting rings are available:
- Zero adjusting ring is used for setup of the device and comprises two rings: a ring for rifling lands and a ring for grooves. The actual sizes are specified on a ring casing.
- Limit adjusting ring is used for check of accuracy of the device and also comprises two rings: a ring for rifling lands and a ring for grooves. The actual sizes are specified on a casing.
The measuring unit is made as a cylinder with centering rollers. The diameter on centering rollers corresponds to the internal diameter of a controlled pipe and is moved along the pipe by means of two leading rolls. The measuring unit consists of a mechanism of movement of the unit and a measuring head. In the body of the measuring head two inductive displacement transducers are installed by means of which the measurements of internal diameter deviations from the nominal rate on rifling lands and on grooves are performed.
The measuring unit is installed into the bore of a controlled pipe and moves automatically along the bore by means of the mechanism of the movement located in the measuring unit. The signal from inductive displacement transducers proportional to a deviation of diameters from nominal rates on rifling lands and on grooves is transferred into the recording unit after processing.