Overview of measurement in accordance with ASTM-D257 & IEC 60093 Standards
IEC 60993 and ASTM D-257 cover test methods for the measurement of volume resistivity and a surface resistivity of insulating materials.This test method is applicable for resistivity measurements generally above 107Ω-cm or 107Ω (per square).
This testing is performed to ensure the material meets required minimum and maximum resistivity values.The testing uses a volume/surface resistivity cell in combination with a megohmmeter.
A sample of the material is placed between two electrodes in the cell, the megohmmeter is then used to measure the resistance, at a specific applied voltage, after 60 seconds. The volume resistivity or surface resistivity is then calculated from the measured resistance using a simple formula.
A similar measurement setup can be used for testing materials in accordance with AATCC 76-2000 for electrical surface resistivity of fabrics and ESD S11.11 for elelctrostatic planar materials. The IET 1865 + Megohmmeter and 1865-11 Test Cell can be combined to make a complete system for measurement of volume and surface resistivity. This combination is used by a number of respected companies and test laboratories for this application. The 1865 Plus can easily be programmed to apply the required voltage to the material and display the resistance after 60 seconds.