Electrical Properties Probe Measures Water/Ice Content of Martian Soils Using Impedance Spectroscopy

We are developing a simple apparatus to quickly determine the amount of water/ice using two probes that contact the regolith. Using impedance spectroscopy, we describe how conductivity measurements were used to determine the amount of water/ice in simulated martian soils. We measured silica sand samples containing 0.05% to 10% water doped with KC1 and MgSO₄ between -65degC and 25degC. Results indicate that we are able to measure the water/ice content of coarse silica sand with > 0.05% water and > 0.5% ice. For a concentration, C*, of ions or defects, water/ice gravimetric content, thetas _g, and equivalent conductivity, Lambda, the conductivity is sigma=2.5x10^-7ldrLambdaldrC*ldrthetas _g ^1.8.