Abstract: A method and a device for determining the state of a rail stretch utilize a receiver that is moved along the rail stretch to receive radio signals transmitted by at least three transmitters mounted in the elevator shaft. Spacing data is determined from the radio signals and is compared by an evaluating unit with reference data of the spacing to generate a result with respect to the state of the rail stretch. The positions of rail fastenings, connecting straps and shaft doors can be detected by additional sensors also moved along the rail stretch and are represented in a correction protocol to permit an efficient adjusting of the rail stretch.

Abstract: A method and a device for determining the rectilinearity of guide rails wherein a guide rail is oriented substantially parallel to a reference axis. At least one light beam is emitted along the reference axis by a light source and is detected by a light detector. When the light source or the light detector is displaced along the guide rail, warping and twisting of the guide rail can be detected as changes in the spacing between the guide rail and the reference axis.

Abstract: A method and a device for determining the state of a rail stretch utilize a receiver that is moved along the rail stretch to receive radio signals transmitted by at least three transmitters mounted in the elevator shaft. Spacing data is determined from the radio signals and is compared by an evaluating unit with reference data of the spacing to generate a result with respect to the state of the rail stretch. The positions of rail fastenings, connecting straps and shaft doors can be detected by additional sensors also moved along the rail stretch and are represented in a correction protocol to permit an efficient adjusting of the rail stretch.