
6
•
Lighting arrestor boards and enclosures are available from Geokon that can be installed
inside the enclosure. The enclosure has a hinged lid, so that if the protection board (LAB-3) is
damaged, the user can service the components (or replace the board). A connection is made
between this enclosure and earth ground to facilitate the passing of transients away from the
gauge. (As shown in Figure 6.)
•
Alternatively, plasma surge arrestors can be included inside the enclosure close to the sensor.
A ground strap would connect the surge arrestor to earth ground, either a grounding stake or
other suitable earth ground.
Consult the factory for additional information on these or alternate lightning protection schemes.
Terminal Box/Multiplexer
Instrument Cable
LAB-3 Enclosure LAB-3 Board
Model 4450 Transducer
Ground Connections
Surface
(usually buried)
(inside extensometer housing)
Extensometer
Figure 6 - Lightning Protection Scheme