Function: The instrument is suitable to calibrate and check all kinds of inclinometers to determine measurement accuracy of dip angle and azimuth angle of inclinometers. Main Technical Characteristics: The non-verticality error between the horizontal axle and central axle and between the vertical axle and the central axle is less than 12′; Each scale division of dip angle dial is 1°; error among scale divisions is not more than ±3′; measurement error using a vernier: <±6′; Each scale division of azimuth angle dial is 2°; error among scale divisions is not more than ±3′; measurement error using a vernier: <±12′; Sensitivity of water level bubble is 4′; Error: <±20%; The instrument can clamp inclinometer with a diameter of φ62-φ76 mm;