EVALUATION OF SYSTEMATIC ERRORS OF STRIP ASYMMETRIC HUMIDITY SENSOR

Abstract

The methodical estimation of the methodical component of the error arising at measurement of humidity of heterogeneous dispersed dielectrics by the band asymmetric sensor is carried out. In the process of evaluation it was shown that the most significant component of methodological error occurs due to changes in temperature and frequency of the information wave. Temperature-dependent values included in the mathematical model of the band asymmetric humidity sensor are: relative dielectric constant of the substrate dielectric and the object of control, length and width of the central conductor, substrate dielectric thickness. The dielectric constant of the dielectric of the object of control depends on the frequency of the information wave, and this parameter is directly included in the coefficients of the sensor conversion equation. The results of the research showed that in the process of measuring the conversion of humidity in the band asymmetric sensor there is a methodological component of the error associated with changes in temperature and instability of the frequency of the information wave. To ensure a frequency error at a level not exceeding 0.5%, the error of instability of the frequency of the information wave when converting humidity into the output amplitude of the information wave should not exceed ± 3 kHz, provided by existing RF generators. It is advisable to remove the temperature component of the error using the method of correction. The mathematical model of band asymmetric measurement of moisture conversion of heterogeneous dispersed dielectrics in the high-frequency region was also improved.