EMIT - Questions And Answers

Among the instruments we make at Zygo, one of them is used to measure magnetic media components (i.e., disk read/write heads). Recently, we have been asked to measure the levels of ESD charge on our instruments. I have an Air Ionizer Tester/Field Meter available and am wondering if there are any standards (i.e., distance from surface being measured?) or processes for conducting ESD measurements? If so, could you please provide me with this information, or tell me where I can get it? - Andy Emars, Zygo Corporation, Middlefield, CT Answers

You will want to follow the manufacturer’s specs for making field measurements with your field meter. Typically these units are manufactured to read a 1:1 reading (actual) at 1 inch from a planar surface (you don’t want to measure curved or pointy surfaces at the field is not consistent and your readings may be misleading. There are no ESD Association standards that specifically guide you to measuring electric fields on equipment. ANSI-EOS/ESD-S3.1-1991 standard on Ionization does use a field meter (charge plate analyzer) to measure the effectiveness of ionizers. In general, the measurements made should follow the manufacturer’s specs, be done in a consistent environment (i.e., same temperature and same RH) as well as all variables be removed (nearby charge generators, (including yourself - ground yourself and cover your clothes with a grounded smock for the hand held field meter)).

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