Bestec offers surveying, installation, alignment and calibration of large machines, especially of customized optical instruments, using laser trackers, 3D measuring arms, theodolites, automatic optical levels and autocollimators. We test the final performance using Bestec customized control systems together with integrated diagnostic tools, e.g., microscopes, autocollimators, residual gas analyzers, position sensitive detectors and digital indicators. For well characterized radiation sources we offer alignment with light.