The "required" resistance depends upon the type of installation. For anything following the NEC, 25 ohms is a target but not a requirement. If one electrode is over 25 ohms, add another and the resulting resistance can be anything. <br>
When it comes to electronic installations...
These are IEEE standards <br>
802.3 (1998) is IEEE Standard for Informtion technology<br>
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802.5 (1998) is IEEE Standard for Information Technology<br>
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These are available from IEEE at 1-800-678-4333<br>
or <A HREF="http://standards.ieee.org/catalog/olis"...