All critical inputs and outputs on the data logger are ESD protected. To be effective, the earth 
ground lug must be properly connected to earth (chassis) ground. 
Communications ports are another path for transients.  You should provide communications 
paths, such as telephone or short-haul modem lines, with spark-gap protection.  Spark-gap 
protection is usually an option with these products; so, request it when ordering. Spark gaps 
must be connected to  earth (chassis) ground.
For detailed information on grounding, see Grounds(p. 13).
20. Installation160