Most storage devices that do not require vision and a brain to read data fall into this category. Electromagnetic data may be stored in either an analog data or digital data format on a variety of media.
Direct Tripwire Alarm - The wire placed across the path is directly connected with the cord, wire or string placed across the particular path. Laser Tripwire Alarm - An invisible laser, typically an infra-red, is used instead of a cord or string.
Locate the central building ground. 7. Use a grounding wire (#10 copper or #8 aluminum) that will extend from the grounding block to the central building ground. Attach the grounding wire to the grounding block by placing it through the wire hole in the grounding block and tightening the screw.rounded interior metal cold water pipe within five feet of the point where it enters the building. Grounded metallic service raceway. Grounded electrical service equipment enclosure. Eight-foot grounding rod driven into the ground (only if bonded to the central building ground by #6 or heavier bonding wire).