A laser rangefinder-based optical coordinate measurement system used for monitoring refractory lining wear in steel mills has been equipped with a vision system to improve its operative and performance characteristics. The 3D shape of the refractory lining is measured after renewal at the beginning of a campaign and these data are stored as a reference. During the campaign the lining is measured and the results are compared against the reference data in order to minimize risks and optimize lining life. To make the results measured at different times comparable, they must be accurately and reliably transformed to the same coordinate system. This makes the coordinate system setup phase critical for the success of the lining wear monitoring. Other important aspects are the amount of expensive process time taken up by the measurements and work safety aspects. The experimental vision system has been tesetd for automating the corrdinate system setup phase, and improved repeatability and faster operation compared with manual setup was achieved. Tentative tests at a steel mill proved promising, and further development of the vision system is going on.