Chauvin Arnoux C.A 6472 User manual

C.A6472
EARTH AND RESISTIVITY TESTER
ENGLISH User's manual

2
Thank you for purchasing a C.A 6472 earth and resistivity tester. To obtain the best service from your unit:
read these operating instructions carefully,
comply with the precautions for use.
PRECAUTIONS FOR USE
This instrument is protected from accidental voltages of not more than 50 V with respect to earth in measurement category IV. The
guaranteed level of protection of this equipment may be compromised if used in a manner not specified by the manufacturer.
Make no measurements on conductors likely to be connected to the network or to earth conductors
that are not disconnected.
Do not exceed the maximum rated voltage and current and the measurement category.
Never exceed the protection limits indicated in the specifications.
Comply with the conditions of use, namely the temperature, the humidity, the altitude, the degree of pollution, and the place of
use.
Do not use the device or its accessories if they seem damaged.
Use only the charging unit supplied with the tester to recharge the internal battery.
Use connection accessories of which the overvoltage category and service voltage are greater than or equal to those of the
measuring device (50V CAT IV). Use only accessories that comply with safety standards (IEC 61010-2-031 and 32).
Troubleshooting and metrological checks must be done only by accredited skilled personnel.
Wear the appropriate protective gear (insulating boots and gloves).
Foreword:
The potentials on the various rods used for an earth measurement may be different if a nearby electrical installation is defective or
certain weather conditions prevail (thunderstorms). It is up to the operator to decide whether to continue or postpone a campaign
of measurements in a given situation.
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WARNING, risk of DANGER ! Refer to the user’s manual.
Failure to perform the instructions in this operating manual preceded by this symbol, or to perform them correctly, may
cause bodily injury or damage to the instrument and the installations.
Equipment protected throughout by double or reinforced insulation.
The rubbish bin with a line through it means that in the European Union, the product must undergo selective disposal
for the recycling of electric and electronic material, in compliance with Directive WEEE 2002/96/EC.
Earth terminal.
Definition of measurement categories:
Measurement category IV corresponds to measurements taken at the source of low-voltage installations.
Measurement category III corresponds to measurements on building installations.
Measurement category II corresponds to measurements taken on circuits directly connected to low-voltage installations.
Measurement category I corresponds to measurements taken on circuits not directly connected to the network.
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CONTENTS
1. START-UP ................................................................................................................................................................................. 4
1.1. Unpacking...................................................................................................................................................................... 4
1.2. Characteristics label...................................................................................................................................................... 4
1.3. Charging the battery ..................................................................................................................................................... 5
2. PRESENTATION OF THE DEVICE........................................................................................................................................... 6
2.1. Functions of the device ................................................................................................................................................ 7
2.2. Keypad........................................................................................................................................................................... 7
2.3. Display unit .................................................................................................................................................................... 8
2.4. Operating principle........................................................................................................................................................ 9
3. AUTOMATIC MODE ............................................................................................................................................................... 10
3.1. Resistance measurement............................................................................................................................................ 10
3.2. 3P earth measurement ................................................................................................................................................ 13
3.3. 4P earth measurement ................................................................................................................................................ 15
3.4. Measurement of soil resistivity r ............................................................................................................................... 18
3.5. Measurement of earth potential V pot........................................................................................................................ 22
3.6. Earth measurements with 2 clamps ........................................................................................................................... 24
4. ERROR REPORTING ............................................................................................................................................................. 25
4.1. Electrode resistance too high ..................................................................................................................................... 25
4.2. Out of range................................................................................................................................................................. 25
4.3. Misconnection ............................................................................................................................................................ 25
4.4. Indicators of limits of use............................................................................................................................................ 25
5. MEASUREMENTS IN MANUAL MODE ................................................................................................................................ 27
5.1. Choice of measurement frequency ............................................................................................................................ 27
5.2. Switching of the measurement voltage...................................................................................................................... 27
5.3. Manual settings for the resistance measurement ..................................................................................................... 28
5.4. Manual settings for the 3P earth measurement ............................................................................................................. 28
5.5. Manual settings for the 4P earth measurement......................................................................................................... 29
5.6. Manual settings for the soil resistivity measurement ................................................................................................ 30
5.7. Manual settings for the earth potential measurement............................................................................................... 30
5.8. Manual settings for the measurement with 2 clamps................................................................................................ 30
5.9. Sweep mode (SWEEP) ................................................................................................................................................ 30
5.10. Smoothing.................................................................................................................................................................. 30
6. MEASUREMENTS WITH THE PYLON BOX ......................................................................................................................... 31
6.1. Description of the C.A 6474 Pylon Box and AmpFLEX sensors .............................................................................. 31
6.2. Measurements in automatic mode ............................................................................................................................. 33
6.3. Error reporting ............................................................................................................................................................. 37
6.4. Manual and sweep modes .......................................................................................................................................... 37
7. MEMORY FUNCTION ............................................................................................................................................................ 39
7.1. Storage of measurement results................................................................................................................................. 39
7.2. Retrieval of stored results ........................................................................................................................................... 40
7.3. Erasure of the memory................................................................................................................................................ 41
8. CONFIGURATION (SETUP) ................................................................................................................................................... 43
8.1. Press the CONFIG key ................................................................................................................................................ 43
8.2. Press the DISPLAY key ............................................................................................................................................... 44
8.3. Press the MEM key...................................................................................................................................................... 44
8.4. Press the MR key ........................................................................................................................................................ 44
8.5. Internal parameters ..................................................................................................................................................... 44
8.6. Check of the display unit ............................................................................................................................................ 45
9. ERROR MESSAGES ............................................................................................................................................................. 46
10. CONNECTION TO A PC AND ANALYSIS SOFTWARE ...................................................................................................... 47
11. SPECIFICATIONS AND TECHNICAL CHARACTERISTICS .............................................................................................. 48
11.1. Reference conditions ................................................................................................................................................ 48
11.2. Electrical characteristics........................................................................................................................................... 48
11.3. Power supply............................................................................................................................................................. 54
11.4. Environmental conditions ......................................................................................................................................... 55
11.5. Characteristics of contruction .................................................................................................................................. 55
11.6. Conformity to international standards...................................................................................................................... 55
11.7. Electromagnetic compatibility .................................................................................................................................. 56
12. TERMS AND DEFINITIONS ................................................................................................................................................. 57
13. GLOSSARY........................................................................................................................................................................... 58
14. MAINTENANCE.................................................................................................................................................................... 60
14.1. Cleaning ..................................................................................................................................................................... 60
14.2. Replacement of the fuse ........................................................................................................................................... 60
14.3. Replacing the battery................................................................................................................................................ 61
14.4. Metrological check.................................................................................................................................................... 62
14.5. Repair......................................................................................................................................................................... 62
15. WARRANTY, SERVICE........................................................................................................................................................ 63
16. TO ORDER............................................................................................................................................................................ 64
16.1. Accessories ............................................................................................................................................................... 64
16.2. Replacement parts .................................................................................................................................................... 65

4
1. START-UP
1.1. UNPACKING
x 5
HX0056-Z
x 5
FR A N Ç A I S
Ohmmètrede terre
Mémento
x 2
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1One line power adapter + 2-pole cable to recharge the battery.
2Data export software + an optical/USB communication cord.
3User manual in 5 languages, on CD-ROM.
45 simplified user manuals (1 per language).
55 characteristics labels (1 per language).
62 C182 clamps with 2 safety leads.
1.2. CHARACTERISTICS LABEL
Affix the appropriate characteristics label to the inside of the cover of the device (labels in five different languages are pro-
vided).

5
1.3. CHARGING THE BATTERY
Charging time: 3h30’
Ω
DC
ALARM
Ω
Ω
H
E
±
AUTO
V
> 110 Vac
< 240 Vac
50 / 60 Hz
OFF
mΩ
mΩ
START/STOP


For a discharging cycle, set the
switch to mΩ.
Short-circuit by connecting
a lead between terminals
H and E.
E
ES
S
H

CONFIG
Switch the device to manual mode. Press the
CONFIG key, then the key, then the CONFIG key
3 times.

CONFIG
x 3
Start the measurement by pressing
the START/STOP button.
Let the measurement continue until the
battery is fully discharged.
MANUAL
Ω
DC
mV
H
E
+
ALARM
mA
V
V
Start by fully charging the battery before the first use. The charging must be done between 0 and 40°C.
After prolonged storage, the battery may be fully discharged. In this case, the first charge may last several hours. To enable the
battery to recover its initial capacity, we recommend performing several successive complete charging/discharging cycles (3 to
5 cycles).

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2. PRESENTATION OF THE DEVICE
E
ES
H S
SMOOTH
DISTANCEMR
DISPLAY
CONFIG./
FREQUENCY
MEM
2nd
SET-UP
OFF
C.A 6472
GROUND TESTER
2 clamps
AmpFLEX
4 poles
3 poles
mΩ
V pot.
START / STOP
2nd
Access the secondary functions of the keys
MEM / MR
Store measure- ments and read the memory
CONFIG/FREQUENCY
DISTANCE
Configure the measure- ments (expert mode)
DISPLAY /
SMOOTH
Display all parame- ters of the measure- ment and smooth measurements
To start the measure- ments and compen- sate for the leads
Choice of meas- urement function or SET-UP
Transfer of data to PC
Charging of battery
Connection terminals
START/STOP

X02870
, and
to configure the measurements and manage the memory
AmpFLEX
C.A 6474
PYLON BOX
Connection of the Pylon Box

7
2.1. FUNCTIONS OF THE DEVICE
The C.A 6472 earth tester is a complete portable measuring device intended for earth measurements, soil resistivity measure-
ments and with the C.A 6474 Pylon box accessory, pylon earth measurements. It is contained in a housing suitable for field use
and supplied by a rechargeable battery with built-in charger.
Measurement func-
tions
: resistance, 2-wire or 4-wire,
earth resistance, 3-point or 4-point
coupling of earth resistances
selective earth resistance
soil resistivity
earth potential
earth resistance with 2 clamps
earth resistance of pylons with the C.A 6474 Pylon box accessory
Control : 9-position switch, 6-key pad, and a START/STOP button
Display : back-lit 108 x 84mm LCD display unit having 3 simultaneous numerical display levels
2.2. KEYPAD
When the buzzer is active ( symbol displayed), the device confirms each key press by an audible beep. A higher-pitched beep
means that the key press is disabled or has no effect.
A long press (more than 2 seconds) is confirmed by a second audible beep.
The functions of the keys are described briefly opposite.
Special case:
To increase a flashing figure or number, press the key.
To decrease a flashing figure or number, press 2nd and . The 2nd symbol remains displayed to indicate that the 2nd key is still
active and does not have to be pressed each time and that the key is directly accessible. To reverse the direction, press the
2nd key again.
To change an item or a frequency, press the key.

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2.3. DISPLAY UNIT
1DANGER symbol.
2Audible tone On.
3A flashing «>» or «<» indicates a value that is out of bounds.
4Indicates the battery charge condition.
5Indicates whether the 3-pole EARTH measurement or the EARTH COUPLING measurement has been selected.
6Indicates the sensitivity of the Pylon Box: x1/10, x1, x10.
7Number of turns of the AmpFLEX current sensors (1 to 4 turns).
8Number of the AmpFLEX coils connected: 1 to 4.
9Object (OBJ) and TEST no. for the storage of results.
10 Lead compensation for 2-wire measurements is active.
11 The DISTANCE function used to enter distances is active.
12 The FREQUENCY function for manual frequency changes during a measurement is active.
13 The 2nd key has been pressed.
14 The MANUAL, AUTO, or SWEEP mode is active.
15 NOISE interfering with the measurement has been detected.
16 The CONFIG mode, allowing modification of the measurement parameters, is active.
17 The MR mode, for the display of stored results, is active.
18 The MEM mode (storage of results) is active.
11
1 2 3 4 5 6 7
12
13
1415161718
19
20
21
22
23
24
25
26
27
28
9
10
8
Fig. 1
W
S
EARTH COUPLING 1 2 3 4 OK
MEMMR CONFIG MANUALAUTO SWEEP
REMOTE
COM
NOISE
0
R
>
<
mV
k Ω m
k Ω ft
DC
AC
OBJ.
ALARM TEST
DISTANCEFREQUENCY
=
>
<
Hz
mA
kΩft
mVA
kΩft
H
S
ES
E
d
dA
d
d
d
d
A
ρ
=
>
<
2nd
SMOOTH
ALL
S x 10 / 10 12
34
±
DC AC

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19 Indicates that the device is remote-controlled by a computer (REMOTE).
20 SMOOTHing of the measurement results is active.
21 Indicates that a clamp must be connected to terminal ES (flashing) or is connected to it (steady).
22 Display of the measured parameter (R, U, I).
23 Rotating arrows indicate that a measurement is in progress.
24 Indicates that the ALARM function is active.
25 Indicates the distances d or/and A.
26 Indicates that a clamp must be connected to terminal H (flashing) or is connected to it (steady).
27 Indicates which of terminals H, S, ES, and E are to be connected according to the measurement function chosen (fixed)
or are missing (flashing).
28 Display of soil resistivity rmeasured by the Wenner or Schlumberger method (rWor rS).
In this user manual, the symbol indicates flashing.
2.4. OPERATING PRINCIPLE
The device has 2 operating modes:
Automatic mode for routine applications,
Manual/Expert mode in which the user can change the parameters of the measurement functions.
2.4.1. AUTOMATIC MODE
Set the switch to the desired function,
Make the connections appropriate to the function,
Press the START button. The device makes the measurement and stops automatically.
Read the measurement result on the display unit and the relevant parameters using the DISPLAY key. You can record all of
this information in the internal memory of the device.
2.4.2. MANUAL OR EXPERT MODE
Set the switch to the desired function,
Make the connections appropriate to the function,
Select “MANUAL” mode.
Choose the various measurement parameters using the CONFIG key.
Press the START button. The measurement frequency or the direction of the current (resistance measurement) can be changed
during the measurement to view their impact upon the measurement and the parameters relevant to the measurement can
be viewed using the DISPLAY key.
When the measurement results are acceptable, stop the measurement by pressing the STOP button.
View the result on the display and toggle through the relevant parameters using the DISPLAY key. You can save all of this
information to the internal memory of the device.
The instrument also incorporates a “SWEEP” mode (automatic execution of several measurements at several different frequencies),
used to indicate how the measurement varies as a function of frequency. In this case, the device operates as in the automatic
mode and the measurement process stops after taking the measurement at the final frequency.
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START/STOP

E
ES
S
H
R
Ω
DC
ALARM
Ω
Ω
H
E
±
AUTO
Ω
DC
ALARM
Ω
Ω
H
E
±
AUTO

DISPLAY
R =
OFF
mΩ
mΩ
E
ES
S
H
START/STOP


2nd
Ω
DC
ALARM
Ω
Ω
H
E
±
AUTO
AUTO
0
R
Ω
DC
AC
ALARM
Ω
H
E
±
3. AUTOMATIC MODE
3.1. RESISTANCE MEASUREMENT
3.1.1. 2-WIRE MEASUREMENT
Set the switch to mΩ.
Connect the resistance to be measured
between terminals H and E. It must not
be live.
Start the measurement by press-
ing the START/STOP button. The device makes a meas-
urement with a positive cur-
rent (R+), then reverses the
direction of the current and
makes another measure-
ment (R-).
(R+) + (R-)
2
To display the measurement parameters, press the DISPLAY key several times.
The device displays the following quantities (see the glossary, §13):
R+, R-, +UH-E, +IH-E, -UH-E, -IH-E, U-Act (UH-E and its frequency), and R∆0if there is compensation for the measurement
leads.
3.1.2. COMPENSATION FOR THE MEASUREMENT LEADS
Lead compensation subtracts the resistance of the test leads from the measured result.
Short-circuit the measurement leads. Start the measurement by pressing
the 2nd key, then the START/STOP
button.
This value will be deducted from all re-
sistance values measured thereafter.
Lead compensation is lost when the select switch is turned to another function.

11
OFF
SET-UP SET-UP

DISPLAY
x 2
ALARM
<
Ω


ALARM
<
Ω


and


DISPLAY
x 3
3.1.3. ALARM FUNCTION
This function exists only for the 2-wire resistance measurement. By default, the visual alarm (the ALARM symbol flashes) and the
audible alarm (the buzzer sounds for a few seconds) are triggered when R < 2Ω. This threshold can be changed using the SET-
UP function.
Set the switch to SET-UP.
To turn the alarm
On or OFF.
To choose a low (<) or high
(>) alarm.
To set the value of the alarm between
1 and 999 Ω.
To complete the adjustment of the alarm.
To access the direction
of the alarm.

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
CONFIG
DC
H
E
±
AUTO
CONFIG

CONFIG
DC
H
E
±
AUTO
CONFIG
DC
H
E
±
AUTO
CONFIG
S
ES
DC
H
E
±
AUTO
S
ES
Ω
DC
ALARM
Ω
Ω
±


CONFIG
E
ES
S
H
R
START/STOP

DC
H
E
±
AUTO
S
ES
Ω
DC
ALARM
Ω
Ω
±
3.1.4. 4-WIRE MEASUREMENT
This measurement is used to improve the resolution (10x better than the 2-wire measurement) for weak resistance values; no
compensation for the measurement leads is needed.
The device must first be configured for the 4-wire measurement.
Press the CONFIG
key
To return to 2-wire measurement, simply repeat this procedure.
Connect the resistance to be measured
in 4-wire mode. It must not be live.
Start the measurement by press-
ing the START/STOP button.
To display the measurement parameters, press the DISPLAY key several times.
The device displays the following quantities (see the glossary, §13):
R+, R-, +US-ES, +IH-E, -US-ES, -IH-E, U-Act (US-ES and its frequency, UH-E and its frequency).
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DISPLAY

13
OFF
3 poles
3 poles
START/STOP

EARTH
AUTO
Ω
Ω
Ω
H
S
E
EARTH
AUTO
H
S
E
mA
mV
Ω

DISPLAY
START/STOP

> 2s
EARTH
AUTO
H
S
E
Ω
kΩ
kΩ
E
ES
S
H
HS
62% d
d > 80 m
3.2. 3P EARTH MEASUREMENT
This function is used to measure an earth resistance with 2 auxiliary electrodes.
There are several measurement methods. We recommend the “62%” method.
Set the switch to “3 poles”.
Plant electrodes H and S to form a straight line with the earth electrode. The distance
between electrode S and the earth electrode is 62% of the distance between electrode
H and the earth electrode; the distance between the electrodes H and S should be at
least 30m.
Start the measurement by
pressing the START/STOP
button.
To display the measurement parameters, press the DISPLAY key several times.
The device displays the following quantities (see the glossary, §13):
RE, US-E, IH-E, U-Act (UH-E and its frequency, US-E and its frequency).
Plus RH, RSif the measurement was started by a long press of START/STOP.
To measure the resistances of electrodes H and S, or if the
resistance of the electrodes is too large (see §4), start the
measurement with a long press of the START/STOP button.
In order to avoid electromagnetic interference, it is best to unwind the full length of each cable from the reel, to keep the cables
as far apart as possible on the ground, taking care not to form loops, and to avoid placing the cables near or parallel to metallic
conductors (cables, rails, fences, etc.). Connect the cables to terminals H and S; disconnect the earth strap, then connect terminal
E to the earth electrode to be tested.

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E
ES
S
H
HS
52% d
d
62% d
72% d
3.2.1 RECOMMENDATIONS FOR A RELIABLE MEASUREMENT
Moving the auxiliary electrodes
Move electrode S towards electrode H by a distance equal to 10% of d and make another measurement. Then move electrode
S again by a distance equal to 10% of d, but towards the earth electrode.
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The 3 measurement results should be the same to within a few percent. If this is the case, the measurement is valid.
If not, electrode S is in the zone of influence of the earth electrode. It will be necessary to increase distance d and repeat the
measurements.
Positioning of the auxiliary electrodes
To make sure that your earth measurements are not distorted by interference, we recommend repeating the measurement with
the auxiliary electrodes placed at a different distance and in another direction (for example rotated 90° from the first alignment).
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If you find the same values, your measurement is reliable. If the measured values are substantially different, it is likely that they
were influenced by earth currents or a groundwater course. It may be useful to drive the electrodes deeper and/or wet the ground
near them to reduce their contact resistance with the soil.
Avoid routing the connecting cables of the earth electrodes near or parallel to other cables (transmission or supply), metallic
conductors, rails, or fences: high test frequencies may cause cross-talk and affect the measurements.
HS
E
H
S
d2
d1

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OFF
4 poles
4 poles
H
S
ES
EAUTO
Ω
Ω
Ω
START/STOP

H
S
ES
EAUTO
Ω
mA
mV

DISPLAY
START/STOP

> 2s
AUTO
H
S
E
Ω
kΩ
kΩ
ES
E
ES
S
H
HS
> 30 m > 30 m
3.3. 4P EARTH MEASUREMENT
3.3.1. MEASUREMENT WITHOUT CLAMP
This function is suited to the measurement of very low earth resistances. It provides better resolution (10x better than 3P meas-
urement) and there is no need to compensate for the resistance of the measurement leads.
Set the switch to “4 poles”. Place electrodes H and S at least 30m apart.
Start the measurement
by pressing the START/
STOP button.
To display the measurement parameters, press the DISPLAY key several times.
The device displays the following quantities (see the glossary, §13):
RE, US-E, IH-E, U-Act (UH-E and its frequency, US-E and its frequency).
Plus RH, RS, UH-E if the measurement was started by a long press of START/STOP.
To measure the resistances of electrodes H and S, or if the
resistance of the electrodes is too large (see §4), start the meas-
urement with a long press of the START/STOP button.
We recommend repeating the measurement with the auxiliary electrodes placed at a different distance and in another direction
(see §3.2.1).
In order to avoid electromagnetic interference, it is best to unwind the full length of each cable from the reel, to keep the cables
as far apart as possible on the ground, taking care not to form loops, and to avoid placing the cables near or parallel to metallic
conductors (cables, rails, fences, etc.). Connect the cables to terminals H and S; disconnect the earth strap, then connect termi-
nals E and ES to the earth electrode to be tested.

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OFF
4 poles
4 poles
START/STOP

H
S
ES
EAUTO
Ω
Ω
Ω
AUTO
mA
VA
H
S
ES
E
Ω

DISPLAY
3.3.2. MEASUREMENT WITH CLAMP (SELECTIVE EARTH)
For this selective earth measurement you need a current clamp, either a C182 (supplied with the device) or an MN82 (available
as an accessory). The C182 clamp is more precise, suited to the measurement of higher currents (up to 40 Arms) and to being
placed on thicker conductors, while the MN82 clamp, which is easier to handle, accepts currents only up to 10 Arms and can
be placed on conductors only up to 20mm in diameter. Use only these two types of current clamp, which are specially designed
to work with the C.A 6472 earth tester.
Set the switch to “4 poles”
.
Place electrodes H and S at least 30m apart so that the potential wells that form around
them do not intersect.
Start the measurement
by pressing the START/
STOP button.
To display the measurement parameters, press the DISPLAY key several times.
The device displays the following quantities (see the glossary, §13):
RSEL, US-ES, IH-E, R-Act (RPASS), U-Act (UH-E and its frequency), I-Act (IES and its frequency).
Plus RE, RH, RS, UE-S if the measurement was started by a long press of START/STOP.
E
ES
S
H
HS
> 30 m > 30 m
RE1 RE2 RE3 RE4
You can now move the clamp and its lead to measure
the other earth resistances, RE2, RE3, etc.
RSEL= RE1
In the case of the
diagram above.
In order to avoid electromagnetic interference, it is best to unwind the full length of each cable from the reel, to keep the cables
as far apart as possible on the ground, taking care not to form loops, and to avoid placing the cables near or parallel to metallic
conductors (cables, rails, fences, etc.).
Connect the cables to terminals H and S. Connect a cable between terminal E and the earth. Connect the clamp to terminal ES;
the device recognises it automatically. Clamp the path of the earth to be checked. Connect the socket of the current clamp to
this same path (connection to terminal ES). Take care not to place the cable of electrode H too close to the current clamp; this is
in order to avoid any transmission of the AC signal to the clamp (especially if you use an MN82 clamp).

17
START/STOP

> 2s
H
S
ES
EAUTO
Ω
kΩ
kΩ
To measure the resistances of electrodes H and S, or if the
resistance of the electrodes is too large (see §4), start the
measurement with a long press of the START/STOP button.

18
OFF
ρ
ρ
W
AUTO
Ω m
m
H
S
ES
E
d
ρ
=
Ω
d
d

CONFIG
W
AUTO
H
S
ES
E
d
ρ
d
d
CONFIG
Hz
V

CONFIG
W
AUTO
H
S
ES
E
d
ρ
d
d
CONFIG
Hz
V

AUTO
H
S
ES
E
ρ
CONFIG
Hz
V
S
A
d
d

CONFIG
AUTO
H
S
ES
E
ρS
A
d
d
Ω m
=
m
m
=
OFF
ρ
ρ
W
AUTO
Ω m
m
H
S
ES
E
d
ρ
=
Ω
d
d

2nd

CONFIG
+
W
AUTO
Ω m
m
H
S
ES
E
d
ρ
=
Ω
d
d
DISTANCE
3.4. MEASUREMENT OF SOIL RESISTIVITY r
To measure the resistivity of the soil, you can choose between the Wenner and Schlumberger methods. The difference between
the two methods lies in the positioning of the electrodes. By default, the device selects the Wenner method, but if you want to
vary the distance between the electrodes, use the Schlumberger method, which allows you to move only 2 measurement elec-
trodes rather than 3.
The soil resistivity measurement with different distances d, and therefore in different layers (in depth) of the soil, can be used to
establish resistivity profiles of the soil in question, which can be useful for geological analysis, the exploration of deposits, hydro-
logical studies, etc., and to determine the location of an earth electrode.
3.4.1. CHOICE OF MEASUREMENT METHOD
By default, the Wenner method is selected. To select the Schlumberger method, proceed as follows:
Set the switch to r.
To confirm and exit.
To switch back to the Wenner method, simply repeat this procedure.
The last measurement method selected (Wenner or Schlumberger) is stored in memory when
the device is switched off.
3.4.2. PROGRAMMING OF THE DISTANCE
The distance can be programmed before or after the measurement. If it is not programmed, only the value of RS-ES will be displayed,
since the value of rremains indeterminate.
Set the switch to r.Press the DISTANCE
key.
x 2

19


W
AUTO
Ω m
m
H
S
ES
E
d
ρ
Ω
d
d
DISTANCE
=

W
AUTO
Ω m
m
H
S
ES
E
d
ρ
Ω
d
d
DISTANCE
=
W
AUTO
Ω m
m
H
S
ES
E
d
ρ
Ω
d
d
DISTANCE
=

puis


2nd

CONFIG
OFF
ρ
ρ
E
ES
S
H
HS ES E
dddp
W
AUTO
Ω m
m
H
S
ES
E
d
ρ
=
Ω
d
d
START/STOP

W
AUTO
m
H
S
ES
E
d
ρ
Ω
d
d
k Ω m
rW= 2.π.d.RS-ES
To select the hun-
dreds (of metres).
To s e l e c t t h e
tens.
To modify the
tens.
To select and modify the metres and
tenths of a metre.
To terminate the program-
ming of the distance.
In the case of the Schlumberger method, it is also necessary to program distance A.
This is done in the same way as for distance d.
3.4.3. WENNER METHOD
Set the switch to r.
Place the 4 earth electrodes on a straight line, at a distance d from one another and at a depth
p < 1/3 d. Distance d must be between 2 and 30m. Connect the cables to the electrodes,
then to terminals H, S, ES, and E.
Program distance d and start the meas-
urement by pressing the START/STOP
button.
then
In order to avoid electromagnetic interference, it is best to unwind the full length of each cable from the reel, to keep the cables
as far apart as possible on the ground, taking care not to form loops, and to avoid placing the cables near or parallel to metallic
conductors (cables, rails, fences, etc.).

20

DISPLAY
OFF
ρ
ρ
E
ES
S
H
HS ES E
p
dd
A
AUTO
H
S
ES
E
ρS
A
d
d
Ω m
=
m
m
=
AUTO
H
S
ES
E
ρS
A
d
d
Ω m
=
m
m
=
START/STOP

START/STOP

> 2s
To display the measurement parameters, press the DISPLAY key several times.
The device displays the following quantities (see the glossary, §13):
rW, RS-ES, d, US-ES, IH-E, U-Act (US-ES and its frequency, UH-E and its frequency).
To measure the resistances of electrodes H, S, ES, and E, or if the resistance of the electrodes is too high (see §4),
start the measurement by a long press of the START/STOP button.
The device displays RP-E and RP-H, then RP-ES and RP-S.
Metallic elements in the ground (railway lines, pipes, etc.) or underground water courses may influence the resistivity of the soil in
a given direction. We therefore recommend making another measurement, with the electrodes aligned 90° from the first measure-
ment, to detect any directional effects. We also recommend making several measurements, with different distances d, to eliminate
local effects that might interfere with the measurement.
The greater the distance between the electrodes and the deeper they are driven, the better the result for the deeper layers of the
ground.
3.4.4. SCHLUMBERGER METHOD
Set the switch to r.Place electrodes S and ES at a distance A apart. Then place electrodes H and E in the same
straight line, at a distance d measured from the midpoint of distance A. Distance d must be
between 2 and 30m. Drive the electrodes to a depth p of not more than 1/3 of d. Connect
the cables to the electrodes, then to terminals H, S, ES, and E.
Program distance d and A
(see §3.4.2.).
Start the measurement
by pressing the START/
STOP button.
W
AUTO
H
S
ES
E
d
ρ
d
d
k Ω m
kΩ
kΩ
W
AUTO
H
S
ES
E
d
ρ
d
d
k Ω m
kΩ
kΩ

DISPLAY
In order to avoid electromagnetic interference, it is best to unwind the full length of each cable from the reel, to keep the cables
as far apart as possible on the ground, taking care not to form loops, and to avoid placing the cables near or parallel to metallic
conductors (cables, rails, fences, etc.).