Testboy TV 455VDE-tester Testboy TV 455 User Manual

Product codes
Testboy TV 455
Page of 76
TESTBOY TV 450 
Earth resistance 
 
48 
 
Figure 5.31: Resistance to earth, measurement of a lighting protection system 
 
Earth resistance measurements, common measurement procedure  
 
‰
 
Select 
EARTH 
function using the function selector switch. 
‰
 
Enable and set limit value(optional). 
‰
 
Connect test leads to the instrument 
‰
 
Connect  the item to be tested (see figures 5.30, 5.31). 
‰
 
Press the TEST key to perform the measurement.. 
‰
 
Store the result by pressing the MEM key (optional). 
 
 
 
Figure 5.32: Example of earth resistance measurement result 
Displayed results for earth resistance measurement: 
R..............Earth resistance, 
Rp............Resistance of S (potential) probe, 
Rc............Resistance of H (current) probe. 
 
Notes
‰
 
High resistance of S and H probes could influence the measurement results. In 
this case, “Rp” and “Rc” warnings are displayed. There is no pass / fail indication 
in this case. 
‰
 
High noise currents and voltages in earth could influence the measurement 
results. The tester displays the “noise” warning in this case. 
‰
 
Probes must be placed at sufficient distance from the measured object.