Campbell Scientific CR200/CR200X-series Dataloggers - Manual (Page 68)

Section 7. Grounding
7.1.1 Lightning Protection
The most common and destructive ESDs are primary and secondary lightning
strikes. Primary lightning strikes hit instrumentation directly. Secondary strikes
induce voltage in power lines or wires connected to instrumentation. While
elaborate, expensive and nearly infallible lightning protection systems are
available, Campbell Scientific has for many years employed a simple and
inexpensive design that protects most systems in most circumstances. It is,
however, not infallible.
Note Lightning strikes may damage or destroy the CR200(X) and associated
sensors and power supplies.
In addition to protections discussed in ESD Protection (p. 55), use of a simple
lightning rod and low-resistance path to earth ground is adequate protection in
many installations. A lightning rod serves two purposes. Primarily, it serves as a
preferred strike point. Secondarily, it dissipates charge, reducing the chance of a
lightning strike. FIGURE. Lightning Protection Scheme (p. 57) shows a simple
lightning protection scheme utilizing a lightning rod, metal mast, heavy gage
ground wire, and ground rod to direct damaging current away from the
CR200(X).
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