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Before setting the earth spikes for probe and auxiliary earth electrode make sure that the 
probe is set outside the potential gradient area of earth electrode and auxiliary earth 
electrode. Such a condition is normally reached by allowing a distance of >20 m between 
the earth electrode and the earth spikes as well as of the earth spikes to each other.  

An accuracy test of the results is made with another measurement following repositioning 
of the auxiliary earth electrode or probe. If the value stays the same, the distance is 
sufficient. If the measured value changes, probe or auxiliary earth electrode must be 
repositioned until the measured value R

E

 stays constant. 

Spike wires should not run too close to each other. 

Use one of the accessory cable drums as earth electrode connecting lead. Spool off 
cable completely and compensate line resistance as described in Compensation of Earth 
Electrode Connecting Lead. 

If there is a warning, MEASURED VALUE UNSTABLE, (see Table 5) after a test 
sequence, most likely it is caused by strong interference signals, such as unsteady noise 
voltage. Nevertheless, to get reliable values, the instrument offers the possibility of 
averaging over a longer period. 

1.  Select a fixed frequency (see Control Loop). 

2.  Keep the "START TEST" button pressed until the warning "measured value unstable" 

disappears. Maximum averaging time is approximately 1 minute.