Selection of the Band-Pass Range of the Normalizing Signal Transducer of the Sensing Element in the Instrumentation and Control Systems

In automatic control systems (ACS), the unifying (normalizing) converter (UC) of the physical magnitude sensor amplifies the signal of the sensing element (SE) to a standard value. In this case, the band-pass range of the UC specifies the value of signal delay time of the SE in the UC. It is shown that the dynamic error of the UC is determined by the signal delay time of the SE and the first derivative of the SE. The response of the UC was approximated by the Butterworth filter response. The use of the Filter Solution application programs in the NI Lab VIEW software environment (Lab View 8.6) enabled to obtain the numeric evaluations of the signal delay time of the SE in the UC. It is shown that for the case of an infinite spectrum the first signal derivative of the SE does not differ from the value obtained with the Bernstein inequality. The final calculations showed a significant effect of the dynamic error on the total error of the sensor, which causes the increase tenfold the band-pass range of the UC in comparison with the signal band of the UC.