10
Measurements are started from low AB values (see Table ExampleSCH Figure 7 and
Figure 8) and we proceed by enlarging the measure, for some AB / 2 values (when the
Sigma value is too high) to avoid certain problems from lateral variations of surface
resistance it is appropriate to re-execute the measurement by increasing the value of MN
/ 2 (re-tie, see Figure 9 and Figure 10 Figure 9), ideally the two measurements should be
the same.
As you can see from the attached table the values of AB / 2 are spaced logarithmically
with 10 values per decade (1-10 m; 10-100m; 100-1000 m; etc.) and initially all MN
values are equal, (Figure 4 ).
When the measurements begin to be noisy (standard deviation> 5% the contact resistance
must be decreased with the methods indicated above to allow greater current flow and
simultaneously increase the MN / 2 distance, as the measurement proceeds if the Sigma
is to exceed at the prefixed value it will be possible to press the execute / modify / repeat
key (Figure 11) and the software (if the measurement had already been performed it will
increase all the values of MN following one of a value equal to ¼, will be simultaneously
updated the values of K from the modification point, we will proceed as above until the
Sigma will again be> 5% and then again it will be necessary to increase MN, pressing the
repeat key measures all the data from the point of modification forward will be increase
by ¼ and proceed until the end of the measures.
F
IGURE
6
-
SAVING
THE
TABLE
Summary of Contents for GEA RM1 1.0
Page 4: ...4 TEST circuit diagram 67...
Page 5: ......
Page 13: ...GEA RM1 9 How to use FIGURE 4 EXAMPLE OF INTEGRAL TABLE FIGURE 5 EXAMPLE WITH SIMPLIFIED VIEW...
Page 15: ...GEA RM1 11 How to use FIGURE 8 FIGURE 7...
Page 16: ...12 FIGURE 9 MEASURE WITH INCREASED MN FIGURE 10 REPEAT MEASURE...
Page 17: ...GEA RM1 13 How to use FIGURE 11 EXECUTE MODIFY REPEAT FIGURE 12 MEASURING EXAMPLE WITH SIGMA 5...
