Garment Testing

- Jul 23, 2019-

IEC 61340-4-9, which is derived from ANSI/ESD STM 2.1 and ANSI/ESD S1.1 [3], specifies three different types of garments:

  • static control garments, which are personnel garments designed for electrostatic charge control;

  • groundable static control garments, which exhibit electrical resistance from point-to-point and from any point or panel on the garments to the groundable point on the garments;

  • groundable static control garment systems, which are garments used to establish the primary ground path for persons to the groundable points of the garments and the connection of the garments to ground, typically through grounding cords.

IEC 61340-4-9 specifies resistance measurements and recommends resistance limits. Required resistance limits are specified in IEC 61340-5-1 [4] and ANSI/ESD S20.20 [5]. These limits are shown in Table 1.

Type of GarmentParameterResistance Limits
Static control garmentsResistance point-to-point< 1.0 x 1011 Ω
Groundable static control garmentsResistance point-to-point and resistance to groundable points< 1.0 x 109 Ω
Groundable static control garment systemsResistance point-to-point and resistance to groundable points< 1.0 x 109 Ω
Total system resistance including person, garment and grounding cord< 3.5 x 107 Ω

Table 1: IEC 61340-4-9, IEC 61340-5-1 & ANSI/ESD S20.20 resistance limits for garments.