METHOD ESTABLISHING FREQUENCY CHARACTERISTICS OF MEASUREMENT CHANNELS IN INFORMATION-MEASUREMENT SYSTEMS Russian patent published in 2003 - IPC

FIELD: information and measurement technology. SUBSTANCE: technical result of method lies in principal possibility of determination of frequency characteristics in undistorted form without execution of norming procedure. Given method employs known procedure consisting in feed of test signal to input of measurement channel and in determination of its spectrum. One measurement channel of information- measurement system is used in the capacity of reference channel and its complex frequency characteristic is determined by way of measurement of amplitude and phase spectra of output signal. Values of complex frequency characteristic is stored, then test signal is fed to inputs of reference and tested measurement channels simultaneously and output signal of reference measurement channel is subtracted from output signal of tested measurement channel to determine degree of difference of complex frequency characteristics of measurement channels. Difference signal is amplified and its amplitude and phase spectra are measured. Test signal acting on inputs of measurement channels is formed from harmonic oscillations of frequency exceeding repetition frequency of test signal by factor of (N+1) in the form of amplitude- modulated oscillation with law of envelope change determined by relation of momentary values of sinusoidal oscillations with frequency multiplicity N equal to number of summed multiple frequencies and equal amplitudes to obtain harmonic oscillations of test signal. EFFECT: determination of frequency characteristic in undistorted form. 4 dwg