In installations for truing up band blades, band-saw blades must be precisely measured, in order to be trued up accurately. The band-saw blade to be trued runs over two deviation stations and is trued up in the upper linear guide area. The invention provides a saw-band guide section (II), in order to measure the pre-tension in the saw blade which creates the desired bowing. Said section is formed by two parallel guide bearers (20), each of which is subdivided into two sub-bearer sections (21 and 22). The band-saw blade is guided on bearing rollers (25) between the guide bearers (20) and guided by dead rolls (26) which are mounted on pivoting carriages (27) into a curve which corresponds to a clothoid arc. A measurement carried out by a measuring bar (30) comprising sensors (31) provides an extremely accurate, constant result in an area practically devoid of stress.