The problem of testing, verification and calibration of length-scales (electronic rangefinders) and angle-scales (geodetic instruments). The calibration of coded levelling rods and the systemic calibration of digital levelling instruments. The calibration on linear comparative baseline in a terrain – the elaboration of measured data. The testing of universal measuring instruments in laboratory conditions - specific problems in testing of instruments with the passive reflection. Some knowledge about the calibration of horizontal circles of angle-measuring geodetic instruments
