Benchware
Essential To The…
Success of any EPA, benchware and associated accessories can help to maximise working efficiency whilst maintaining an electrostatic safe area.
In accordance with the BS EN 61340-5-1 Standard, all working surfaces (and racks, shelves, etc.) need to be capable of being grounded and to have a point-to-point resistance (Rp) as defined in the table below.
In some cases this surface to ground resistance need not be a discrete resistor but can be through the material which is directly grounded. (The ESD co-ordinator must ensure that this technique does not compromise operator safety). EPA grounding of instruments or surfaces by chaining or by placing items in series should not be used as, in the event of a broken connection, the risk of floating items and ESD damage will be unnecessarily increased.When combined with benchtop accessories such as earth bonding points, ground cords and adaptors as well as chairs, shelf liners and EPA kits, a complete benchware package can be put together to provide a self-contained work area that is fully compatible with the EPA requirements of BS EN 61340-5-1.
ESD Protective Item Requirements
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Item Requirements
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Surface Resistance (Rs) OR
End-to-end Resistance (Re) OR
Point-to-point Resistance (Rp)
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Resistance to EPA Ground OR
Groundable Point (Rg)
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Charge Decay
(SEE NOTE 1) |
| Working surfaces, storage racks, trolleys and carts |
1 x 10^4 Ω Rp 1 x 10^10
See note 2
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7.5 x 10^5 Ω Rg 1 x 10^9
See note 2
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| Seating |
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Rg Ω 1 x 10^10 |
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| Tools |
See note 3 |
Rg Ω 1 x 10^12
See notes 3 and 4
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To 10% of initial values (maximum 1000V) in less than 2
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Note 1: Only mandatory where surface resistance, point-to-point resistance or resistance to groundable point >10^10 Ω or where material is of non-homogenous woven or other construction containing insulating areas. Note 2: It is allowed, when approved by the ESD co-ordinator, to use surfaces that are ‘hard ground’, i.e. less than 1 x 10^4 Ω to EPA ground. Note 3: This refers to BS EN 61340-5-2, which covers a wide range of tools from small hand tools to large machinery. It points out that it is impractical to quantify all appropriate grounding systems for such a wide spectrum of products. Therefore, recommending the resistance to ground specified as a target for any of these items that may come into contact with any ESDS. Note: There is no minimum value of resistance for the protection of ESDS. However, a minimum resistance value may be required for protection or safety. See relevant national requirements and/or IEC 61010-1, IEC 60479, IEC 60536 and IEC 60364.
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