Humidity dependence of apparent dielectric constant for DSP cement materials at high frequencies

The relationship between humidity and dielectric constant for cement densif ied with small particles (DSP) has been studied in the relative humidity ra nge 0%-93% and the frequency range 1 MHz to 1 GHz. The calculated dielectri c constant appears to increase with increasing humidity as a linear relatio n at fixed frequency. According to experimental data and basic principles f or dielectrics, two experimental expressions are suggested for heterogeneou s dielectric materials to describe the observed behavior of the dielectric constant. The expressions fit the experimental data well in the frequency r ange studied. Apparent dielectric constant decreases with increasing freque ncy. Polarization of DSP cement is also discussed.