The development of the NIST Super Shaker permits calibration of accelerometers by two independent and absolute methods on the same shaker. Minimizing the uncertainty of reciprocity calibrations imposes stringent requirements for distortion and cross-axis motion. Laser interferometer calibrations require very low coupling between the shaker and the interferometer components. The design of the Super Shaker provides for very low distortion and cross-motion with very low mechanical coupling between the shaker and optical components. The shaker is equipped with dual coils and two retractable magnets to provide for reciprocity measurements without attaching a driving shaker. These features enhance the convenience with which the Super Shaker can be used to perform both reciprocity and laser interferometer calibrations. This paper describes the shaker and calibration system and gives a comparison of calibration results from the two methods.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.