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CONDUCTIVITY
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Your Ref: |
9962 |
| Our Ref: | 5487/T680 | |
| Enquiries: | P. Heigers | |
| Tel: | (012)428-6549 | |
| Fax: | (012)428-6854 | |
| Date 23 November 2000 | ||
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Continental Conveyors & Systems (Pty) Ltd Attention: Mr. D. Maree P. O. Box 2409 BENONI 1600
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CONVEYOR ROLL- Resistivity/Conductivity Test
Further to your order No: 9962, dated 4 October 2000, I have examined and tested two "yelorolls" for selective compliance with the relevant requirements of SABS IEC 60079-0 and EN 50 014:1993 "Electrical apparatus for potentially explosive atmospheres; Part 0: General requirements" incorporating requirements for measuring resistivity and conductivity of materials and wish to comment as follows:
The test for surface resistivity and conductivity was done in an accordance with clause 7.3.1 of EN 50 014:1993 "Electrical apparatus for potentially explosive atmospheres-General requirements" and clause 22.4.7 of SABS IEC 60079-0 "Electrical apparatus for gas atmospheres". The insulation resistance was measured and the following results were recorded:
i) Sample 1
Average current measured between conductive lines = 0.15ľA
Applied Voltage Ua = 500V, and
R = 500/0,15 x 10-9
= 3.33 GΩ
ii) Sample 2
Average current measured between conductive lines = 0.8ľA
Applied Voltage Ua = 500V, and
R = 500/0.8 x 10-9
= 0.625GΩ
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South African Bureau of Standards |
Suid-Afrikaanse Buro vir Standaarde |
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Page/Bladsy 2 |
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In practice this means that because of its high insulation resistance, Sample 1 will be classified as static material which results in the ability of the material to store large amounts of electronic charge leading to a hazardous situation when discharging. |
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Sample 2 can be classified as non-static due to its low resistance. |
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Yours faithfully |
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Signature on original document but not on world wide web. F du'Lait: GROUP LEADER EXPLOSION PREVENTION TECHNOLOGY |
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