How can I choose the best ESD ionizer, and how should I verify them?

A charge plate monitor can be used to verify that an ionizer is in proper working order. A charge pate works like this: An electrical potential is applied to a metal plate of fixed size and capacitance. A non-contacting voltmeter reads the applied potential. A timer measures the time it takes an ionizer to neutralize the plate potential usually from 1000 volts to less than 100 volts. Other ranges can be established depending on the application. The test methods most often used are available from the ESD Association at www.horb.com.cn.

Another important test for ionizers is to determine the balance of the ionization process. It is optimal if an ionizer produces and delivers a near equal amount of positive and negative air ions. If an ionizer is off-balance, it can actually charge a surface. The balance is measured using the same equipment described above, only in a slightly different mode. Most ionizers today are fairly stable in performance. They should be verified for performance probably quarterly or twice a year depending on your program requirements. For more information on testing ionizers and application of ionizers, contact the ESD Association as mentioned above. There is a Standard ANSI/ESD S20.20 and other information that could assist you for nominal dollars.