Table 2, Footnote 7 states: “The required limit of < 1.0 x 109 ohm is the "maximum" allowed value

ESD Control Program Auditing
#1

Table 2, Footnote 7 states: “The required limit of < 1.0 x 109 ohm is the “maximum” allowed value. The user should document the resistance values that were measured for product qualification for the footwear and the flooring system to comply with the < 100 volts body voltage generation and use these resistances for compliance verification.”
Does this mean that the “highest” resistance value obtained in product qualification of the Footwear/Flooring System will be the internal allowable limit for compliance verification?

#2

This footnote is saying that when you conduct product qualification of the footwear and the flooring system (which are both resistance-based measurements), this data should be compared to the body voltage generation data from ANSI/ESD STM97.2, see below for an example:

  • If an organization’s product qualification data shows that footwear measures 1.0 x 106 ohm, and the flooring system measures 1.0 x 106 ohm, both are well below the required < 1.0 x 109 ohm limit.
  • When combined and measured per ANSI/ESD STM97.2 the organization measures peak voltages of 95V, almost at the limit for body voltage (< 100V).
  • In this situation, there is still margin on the footwear and flooring system’s resistance and little margin on the body voltage generation.
  • It is likely that if either the footwear or the flooring system’s resistance increases from 1.0 x 106 to a higher value (e.g., 1.0 x 107 or 1.0 x 108 ohm) the body voltage will exceed the 100V requirement.