A METHOD OF MEASURING TEFLON MEMBANE SURFACE POTENTIAL FOR ELECTRET MICROPHONES
This paper presents a method for measuring the membrane surface potential for electrets microphones, which are constructed using different varieties of teflon, type polymers like fluoro ethylene propylene (FEP) and per-fluoro-alkoxy (PFA). A polarization and re-polarization method is described, using intense electric fields, and also a procedure to measure surface potential of polarized electrets. The tests are conducted to stabilize this potential. The experimental results have indicated that the surface potential is influenced by the parameters of polarization process: voltage level, potential of protection grid and also by the parameters of polarization chamber: temperature, pressure and humidity.
Keywords: teflon - type polymers, electret, surface potential