1. With the selector switch in the ’OFF’ position, connect the instrument
as shown in Figure 5.
2. Set the selector switch to the 3 point resistance measurement setting
marked ‘3P’.
3. Press and release the TEST button [by pressing and holding the TEST
button, the resistance measurement will be continually updated and
displayed].
4. The instrument will then check for ground noise, the parameters of the
current and voltage circuits and the integrity of the fuse.
5. A resistance reading will be displayed on the LCD display, as shown in
Figure 6.
Figure 6: Three point resistance and four point resistivity reading
Four-terminal ground rod resistance measurement (DET4TD)
In circumstances where the lead resistance could introduce unacceptable
levels of error, the effect can be removed from the measured resistance
using the method below.
1. With the selector switch in the ‘OFF’ position, connect the instrument
as shown in Figure 5, with the lead shown dotted connecting terminal
‘C1’ to the earth electrode (rod) under test.
2. Set the selector switch to the 4 point resistance measurement setting
marked ‘4P’.
3. Press and release the TEST button [by pressing and holding the TEST
button, the resistance measurement will be continually updated and
displayed].
4. The instrument will then check for ground noise, the parameters of the
current and voltage circuits and the integrity of the fuse.
5. After a short period, a resistance measurement reading is displayed.
6. A resistance reading will be displayed on the LCD display, as shown in
Figure 6.
Ground resistance measurement (DET4TD)
Figure 7: Connections for measuring four-terminal soil resistance
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