R - Ground Resistivity Measurement - Amprobe GP-2A Manual De Uso

�CAUTION
When starting measurement the input interfering voltage is measured at both the volt and
ampere circuit. Should it range between 3 V and 9 V, the instrument carries out measurement
and displays the symbol � indicating the uncertainty decline of the measurement (§ 9.1)
9. When the test is over, should the earth resistance value be lower than the full scale, the
instrument emits a double tone indicating the positive outcome of the test and displays
the resistance measurement as well as the interfering voltage value at the time of
measuring
�CAUTION
The resistance 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
10. When the test is over, should the earth resistance 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
11. The measurements can be stored pressing the SAVE key twice (§ 5.1)

4.5 r - Ground Resistivity Measurement

The ground resistivity value is an essential parameter to calculate the resistance value of the
earth rods to be used for the earth installation's construction. The measurement is effected
according to standards IEC 781, VDE 0413 EN61557-5.
�CAUTION
• The instrument can be used for voltage and current measurements on installations with
over voltage category equal to CAT III 240V to earth and maximum voltage of 415V between
inputs. Do not connect the instrument to installations whose voltages exceed the limits
indicated in this manual. Exceeding such limits may cause electric shock to the user and
damage the instrument
• Always connect the cables to the instrument and to the alligator clips when the latter are
not connected to the plant under test
• Always respect the Hand-held area of probe (see 4.2)
• If the length of the supplied cables isn't suitable for the plant under test (see Par. 11), You
can create your own extensions following indications in Par.11.2.1
(Earth resistance measurement)
(Input interfering voltage value)
(Earth resistance measurement higher than full scale)
(Input interfering voltage value)
11