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.