This paper discusses the design features of QCW-1A tester. By selection and conversion of the coordinate systems, the feasibility that the strapdown mounting of gyroscope and accelerometer directly in the moving bodies replaces the mechano-electric platform is explained. Several problems affecting the measuring accuracy and measures used for improving accuracy are analysed. The performances of the unit are tested in the laboratory and in the automobile. Finally, the comparative curves of QCW-1A with U.S. SA-07 inertial tester are given.