TDI ESD Chairs Resistance to Groundable Point Test Positions
ESD SPECIFICATIONS:
Surface Resistivity
- Fabric: Grade III ESD Fabric – 4.5×106 Average (BS6524: 1984)
- Vinyl: Grade III ESD Vinyl – 108 Ohms/Sq or lower (ASTM D-257)
Rate of Decay – 5000 Volts down to 500 Volts
- Fabric: Grade III ESD Fabric – .20 Seconds (apex.)
- Vinyl: Grade III ESD Vinyl – .35 Seconds (apex.)
Figure 1 – Setup for 1 Wheel Measurement; Other 4 Wheels on Insulative Support Surface
RH: 24.4%
Temp: 23.8C
Vinyl Chair Test Results
| 1 Wheel | A | B | C | D | E | |
|---|---|---|---|---|---|---|
| Seat | 2.6E7 | 2.9E7 | 3.2E7 | 3.4E7 | 3.5E7 | (ohms) |
| Foot Rest | 4.7E2 | 8.5E3 | 5.0E2 | 3.9E3 | 3.8E3 | |
| Back | 9.8E7 | 1.1E8 | 8.1E7 | 6.6E7 | 7.5E7 | |
| 2 Wheels | E-A | A-B | B-C | C-D | D-E | |
| Seat | 3.5E7 | 3.5E7 | 3.6E7 | 3.7E7 | 3.6E7 | (ohms) |
Figure 2 – Identifying the Wheels (A-E)
ESD Chair Features:
- CASTERS Standard: Conductive Die Cast Steel Dual Wheel Caster with Brake
Optional: Conductive Die Cast Steel Dual Wheel Caster without Brake - Spring loaded clip in back upright makes connection between back and control.
- Footring – Metal to metal cylinder contact.
- Testing – All chairs are tested for continuous path to ground from seat and back before shipment.