Contactless method of resistance measurement

A contactless method to measure the resistance is suggested that allows one to calculate the distribution of the resistance over the sample with a step of 0.1 mm in the resistance range 107−1013 Ω (polyethylene, silicon dioxide, and other high-resistivity materials). In the course of measurement, the sample must be on a nonconductive substrate. The system is charged (or discharged) with a needlelike electrizer, and a charge (or discharge) current pulse is detected. The amplitude of the pulse grows with conductivity of the sample and therefore can be used to measure its resistance. Using this method, one can quickly determine, e.g., the photoconductivity of the material and temperature dependence of the resistivity or estimate how, say, the air humidity or a nearby radioactive source influences the conductivity. With the resistance of the sample known, one can find, for example, the humidity of the environment, illuminance, or radioactive radiation intensity.