Fluke Fluke 4325155 User Manual

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Follow the steps in Table 6. See Figure 11 for steps 1-5. 

1.  External voltage (Uext) too high  

If the external voltage applied to the instrument is too high, usually from leakage currents in the 
system under test, no measurement can be started (see Specifications for Uext limit).  
Hint:  Reposition probe (S/P2) and restart measurement. 

2.  Auxiliary earth electrode resistance (RH) too high  

If the auxiliary earth electrode resistance is too high it is not possible to drive the current 
necessary for reliable measurements. The measurement is blocked (see Specifications for Rh 
limit). 
Hint:  Check connection of test lead with terminal H/C2, check auxiliary earth stake. 

3.  Probe resistance (Rs) too high 

If the probe resistance is too high measurements are not reliable. The measurement is blocked 
(see Specifications for Rs limit). 
Hint:  Check connection of test lead with terminal S/P2, check probe stake. 

4.  Weak batteries 

If the batteries are weak, the supply voltage may break down during measurement. If there is 
enough energy to complete the measurement “

” symbol is displayed – measurement results 

are valid. If not, a reset occurs. 
Hint:  Replace batteries. Use 6 alkaline AA-type (LR6) batteries. 

5.  Is your R

A

Probe S/P2 must be outside the potential gradient areas of E/C1 and H/C2 for accurate 
measurements. Normally a probe distance of more than 20 m is sufficient. However, in some 
environmental conditions where the soil resistivity is variable, this may not be sufficient. To be 
sure, reposition the probes and take several measurements. If the readings are approximately 
the same, your measurement results are reliable. If not, increase the probe distance. 

6.  Is the result of a “Stakeless ground loop measurement” reliable? 

Ensure that you have the correct inducing clamp (see Accessories). 
The clamp parameters are suited for this test method. An undefined clamp will give incorrect 
results. 
Ensure that the recommended minimum distance between the current clamp is kept. If the 
clamps are positioned too close together, the magnetic field of the inducing clamp will influence 
the sensing current clamp. To avoid mutual influencing, the distance between the clamps can be 
varied and a new test performed. If the measurement values vary only a little or not at all, the 
value can be regarded as reliable.