Study of “hot spots” arising from non-homogeneity in the micro-structures of dissipative materials

DC resistance testing using standard commercial electrodes has been a simple, standard way adopted by many for their evaluation of dissipative materials. However, we have observed that this test is ineffective for the detection of ldquohot spotsrdquo arising from non-homogeneities in the micro-structures of some dissipative materials. We have employed a combination of tests using a direct sharp tip probe for both resistance and charge decay measurements and a small non-contact electrostatic voltmeter for localized surface voltage measurements. These combined tests furnish better information about ldquohot spotrdquo characteristics and their formation in dissipative materials. We wish to share the test techniques, the results and the analysis of our present study.