Originally defined distribution and distribution density functions are used to determine the change of the static characteristics of nonlinear elements caused by the presence of measurement noises. It is shown that the measurement noises may cause significant decrease of the effective gain of the amplifier with saturation and may cause disappearance of the dead zone of the amplifier with dead zone. Theoretical considerations are confirmed by the performed simulations of the closed loop (CL) control system with high gain, saturation and measurement noise. The influence of the measurement noises on the quality of control of the CL system with high gain and saturation is discussed.