The gyrotachometer is designed to measure the angular velocity of rotation of a movable base around one of the axes, which is called the input or measuring axis. The problem is reduced to solving a linear differential equation with constant coefficients. However, the gyrotachometer reacts to rotation around other axes of the bases, the so-called extraneous ones. At the same time, constant, or rather, slowly changing deviations or deviations are observed, which cannot be explained in any way by the properties of a linear equation with constant coefficients.