Questions And Answers

To measure electrostatic charge use a Field Meter. Note a charge will naturally dissipate so to measure a static field cause contact and separation by rubbing the surface to be tested. Then measure the charge the material is able to generate.

To verify EPA Compliance to ANSI/ESD S20.20 note most all “Required Limit[s]” of the Tables of ANSI/ESD S20.20-2007 are resistance in ohms. This is easier to measure using a Surface Resistance Test Kit.

The Table for Compliance Verification notes to test per ESD TR53, that is to check that items in your ESD Protected Area, are proper and properly grounded. All tests are resistance to ground.

You can purchase a copy of ESD Association Technical Report TR53-2006 Compliance Verification of ESD Protective Equipment and Materials from www.ESDA.org.  Its purpose “is to provide periodic verification test methods and troubleshooting guidance for ESD protective equipment and materials to assist the user when complying with the Compliance Verification Plan Requirements of ANSl/ESD S20.20.”

Note: Fundamental ESD Control Principles “The fundamental ESD control principles that form the basis of this document are:

A. All conductors in the environment, including personnel, shall be bonded or electrically connected and attached to a known ground or contrived ground (as on shipboard or on aircraft). This attachment creates an equipotential balance between all items and personnel. Electrostatic protection can be maintained at a potential above a “zero” voltage ground potential as long as all items in the system are at the same potential.

B. Necessary non-conductors in the environment cannot lose their electrostatic charge by attachment to ground. Ionization systems provide neutralization of charges on these necessary non-conductive items (circuit board materials and some device packages are examples of necessary non-conductors). Assessment of the ESD hazard created by electrostatic charges on the necessary nonconductors in the work place is required to ensure that appropriate actions are implemented, commensurate with risk to ESDS items.

C. Transportation of ESDS items outside an ESD Protected Area (hereafter referred to as “EPA”) requires enclosure in static protective materials, although the type of material depends on the situation and destination. Inside an EPA, low charging and static dissipative materials may provide adequate protection. Outside an EPA, low charging and static discharge shielding materials are recommended. While these materials are not discussed in the document, it is important to recognize the differences in their application. For more clarification see ANSI/ESD S541.” [ANSI/ESDS20.20 section Foreword]