Anomalous Measuring Applications - All Modes - Amprobe GP-2A Manual De Uso

�CAUTION
The resistivity measurement is effected with 4-wire volt ampere method without being
affected by the resistance value of the cables. It is therefore not necessary to effect
compensation of cable resistance or of any extension.
13. When the test is over, should the ground resistivity value be higher than the full scale,
the instrument emits a long tone indicating the negative outcome of the test and
displays the screen below
�CAUTION
The full scale is calculated as PMAX = 2 DIST R where DIST is the value set for the distance
among the rods and R the maximum resistance value which can be measured by the
instrument. The full scale of ground resistivity measurement depends on the setting of the
distance among the rods
14. The measurements can be stored pressing the SAVE key twice (§ 5.1)
4.5.1 Anomalous measuring applications – all modes
1. When starting a measurement the instrument checks the continuity of measuring cables.
If the volt circuit (red cable S and green cable ES) is interrupted or its resistance value is
too high, the instrument displays a screen similar to the one below. Check that terminals
are properly connected and that the earth rod is connected to terminal S and not driven
into a pebbly or scarcely conductive ground. In this latter case pour water around the
rod to decrease its resistance value (§ 11.2).
RP>top is displayed when:
The S rod's resistance RS > 50KΩ is summed up to the volt circuit
The resistance of rod S exceeds the value 1200 + 100 RX [Ω] (where RX is the earth
resistance value)
2. When starting a measurement the instrument checks the continuity of measuring cables.
If the ampere circuit (blue cable H and black cable E) is interrupted or its resistance
value is too high, the instrument displays a screen similar to the one below. Check that
terminals are properly connected and that the earth rod is connected to terminal H and
not driven into a pebbly or scarcely conductive ground. In this latter case pour water
around the rod to decrease its resistance value (§ 11.2).
RC>top is displayed when:
(Measurement of ground resistivity higher than the full
scale)
(Value of input interfering voltage and rods' distance set)
(Volt circuit's resistance too high)
(Value of input interfering voltage)
(Example for 3W mode)
14