AEMC 6472 User manual

DIGITAL GROUND RESISTANCE
AND SOIL RESISTIVITY TESTER
ENGLISH User Manual
6472

Statement of Compliance
Chauvin Arnoux®, Inc. d.b.a. AEMC®Instruments
certifies that this instrument has been calibrated
using standards and instruments traceable to
international standards.
We guarantee that at the time of shipping your
instrument has met its published specifications.
An NIST traceable certificate may be
requested at the time of purchase, or obtained
by returning the instrument to our repair and
calibration facility, for a nominal charge.
The recommended calibration interval for this
instrument is 12 months and begins on the date of
receipt by the customer. For recalibration, please
use our calibration services. Refer to our repair
and calibration section at www.aemc.com.
Serial #: ________________________________
Catalog #: ______________________________
Model #: 6472
Please fill in the appropriate date as indicated:
Date Received: _________________________________
Date Calibration Due: _______________________
Chauvin Arnoux®, Inc.
d.b.a AEMC®Instruments
www.aemc.com

READ CAREFULLY BEFORE
USING FOR THE FIRST TIME
Your instrument is equipped with a NiMH battery. This technology o󰀨ers several
advantages:
• Long battery charge life for a limited volume and weight.
• Possibility of quickly recharging your battery.
• Signicantly reduced memory e󰀨ect: you can recharge your
battery even if it is not fully discharged.
• Respect for the environment: no pollutant materials such as lead
or cadmium, in compliance with the applicable regulations.
After prolonged storage, the battery may be completely discharged. If so, it must
be completely recharged.
Your instrument may not function during part of this recharging operation.
Full recharging of a completely discharged battery may take several hours.
NOTE: In this case, at least 5 charge/discharge cycles will be necessary
for your battery to recover 95% of its capacity.
To make the best possible use of your battery and extend its e󰀨ective service life:
• Only use the charger supplied with your instrument. Use of
another charger may be dangerous.
• Only charge your instrument at temperatures between 0° and 40°C.
• Comply with the conditions of use dened in the operating manual.
• Comply with the storage conditions specied in the operating
manual.
NiMH technology allows a limited number of charge/discharge cycles depending
signicantly on:
• The conditions of use.
• The charging conditions.
Please refer to § 9.5 for correct replacement of the battery.
Do not dispose of the battery pack with other solid waste. Used batteries
must be entrusted to a qualied recycling company or to a company
specialized in processing hazardous materials.

2 Ground Resistance Tester Model 6472
Table of Contents
1. INTRODUCTION............................................................................... 5
1.1 International Electrical Symbols...........................................................6
1.2 Denition of Measurement Categories.................................................6
1.3 Receiving Your Shipment.....................................................................6
1.4 Ordering Information ............................................................................6
1.4.1 Kits, Accessories and Replacement Parts ..............................7
2. PRODUCT FEATURES ...................................................................... 9
2.1 Description ...........................................................................................9
2.2 Key Features......................................................................................10
2.3 Control Features ................................................................................11
2.4 Display ...............................................................................................12
2.5 Button Functions ................................................................................14
3. SPECIFICATIONS........................................................................... 15
3.1 Reference Conditions.........................................................................15
3.2 Electrical.............................................................................................15
3.2.1 Frequency Measurements ....................................................15
3.2.2 Voltage Measurements .........................................................15
3.2.3 Current Measurements .........................................................16
3.2.4 DC Resistance Measurements .............................................17
3.2.5 AC Earth Resistance Measurements....................................18
3.2.6 Soil Resistivity Measurement ρ ............................................20
3.2.7 Earth/Ground Potential Measurements V Pot.......................21
3.2.8 Earth/Ground Measurements with 2 Clamps........................22
3.3 Data Storage......................................................................................22
3.4 Power.................................................................................................22
3.5 Mechanical.........................................................................................23
3.6 Environmental ....................................................................................23
3.7 Safety.................................................................................................24
4. OPERATION .................................................................................. 25
4.1 General Operating Instructions ..........................................................25
4.1.1 Automatic Mode....................................................................25
4.1.2 Manual (Expert) Mode ..........................................................25
4.2 Instrument Conguration (SET-UP mode) .........................................26

Ground Resistance Tester Model 6472 3
5. AUTOMATIC MODE........................................................................ 27
5.1 Switching the Test Voltage .................................................................27
5.2 Resistance Measurement mΩ (2-Wire)..............................................27
5.2.1 Lead Compensation Measurement ......................................28
5.2.2 Alarm Function......................................................................29
5.3 Resistance Measurement mΩ (4-Wire)..............................................30
5.4 Earth/Ground Measurement (3-Pole).................................................31
5.4.1 62% Method..........................................................................31
5.4.2 Full Method ...........................................................................33
5.4.3 Recommendations for a Reliable Measurement...................33
5.5 Earth/Ground Measurement (4-Pole).................................................35
5.5.1 Measurement without a Clamp .............................................35
5.5.2 Measurements with a Clamp ................................................36
5.6 Soil Resistivity Measurements (ρPosition)........................................38
5.6.1 Advantages/Disadvantages of Wenner and Schlumberger ..38
5.6.2 Changing the Measurement Method.....................................39
5.6.3 Programming the Distance for Electrode Placement............39
5.6.4 Wenner Method ....................................................................40
5.6.5 Schlumberger Method...........................................................42
5.7 Potential Measurement (V pot) ..........................................................43
5.8 Earth/Ground Measurements with Two Clamps.................................45
6. MANUAL MODE ............................................................................ 47
6.1 Switching the Test Voltage .................................................................47
6.2 Measurement Frequency Selection ...................................................48
6.3 Manual Settings for mΩ Measurements ............................................48
6.3.1 Continuity Test ......................................................................49
6.4 3-Pole Earth/Ground Measurement & Coupling .................................. 49
6.4.1 3-Pole Earth/Ground Measurements ....................................49
6.4.2 Earth/Ground Coupling Measurements ................................49
6.5 4-Pole Earth/Ground Measurements .................................................51
6.6 Soil Resistivity Measurements ...........................................................51
6.7 Earth/Ground Potential Measurements..............................................51
6.8 Measurements with Two Clamps .......................................................51
6.9 SWEEP Mode ....................................................................................52
6.10 Smoothing..........................................................................................52

4 Ground Resistance Tester Model 6472
7. MEMORY FUNCTION ..................................................................... 53
7.1 Saving Measurements into Memory...................................................53
7.2 Recalling Measurements from Memory .............................................54
7.3 Erasing Measurements from Memory................................................54
7.3.1 Erasing All Measurements ....................................................54
7.3.2 Erasing Selective Measurements .........................................55
8. DATAVIEW®SOFTWARE ................................................................ 56
8.1 Installing DataView®...........................................................................56
8.2 Ground Tester Control Panel..............................................................58
9. MAINTENANCE ............................................................................. 59
9.1 Maintenance.....................................................................................59
9.2 Cleaning...........................................................................................59
9.3 Fuse Replacement...........................................................................59
9.4 Recharging the Battery ....................................................................61
9.5 Replacing the Battery.......................................................................62
10. TROUBLESHOOTING ...................................................................... 64
10.1 Error Reporting.................................................................................64
10.1.1 Electrode Resistance Too High.............................................64
10.1.2 Out of Range.........................................................................64
10.1.3 Misconnection ......................................................................64
10.1.4 Out of Limits Indicators .........................................................65
10.1.5 Error Messages.....................................................................67
APPENDIX A: GLOSSARY OF TERMS................................................... 68
Basic Terminologies ....................................................................................68
Glossary ......................................................................................................69
Repair and Calibration....................................................................... 72
Technical and Sales Assistance......................................................... 72
Limited Warranty ............................................................................... 73
Warranty Repairs............................................................................... 73

Ground Resistance Tester Model 6472 5
CHAPTER 1
INTRODUCTION
WARNING
These safety warnings are provided to ensure the safety of personnel.
Please read and comply with these precautions:
• This instrument is protected from accidental voltages of not more than
50V with respect to earth in measurement CAT IV. The guaranteed level
of protection of this equipment may be compromised if used in a manner
not specied by the manufacturer.
• Safety is the responsibility of the operator.
• All metal objects or wires connected to the electrical system should be
assumed to be lethal until tested. Grounding systems are no exception.
• Never exceed the maximum rated voltage and current, and the mea-
surement category.
• Never exceed the protection limits, and always comply with the condi-
tions and place of use, indicated in the specications.
• Do not use the instrument or its accessories if they appear damaged.
• Use accessories that have overvoltage category and service voltages
greater than or equal to those of the instrument (CAT IV 50V). Use only
accessories that comply with safety standards (IEC 61010-2-031 & 32).
• Wear the appropriate protective gear (insulating boots and gloves).
• Check that no terminal is connected and the switch is set to OFF before
opening the device.
• Use only the charging unit supplied with the instrument to recharge the
battery.
• Troubleshooting and metrological verication procedures must only be
performed by qualied, approved personnel, or the factory.
• NOTE: The potentials on the various rods used for an earth measurement
may be di󰀨erent 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 measurements in these
situations.

6 Ground Resistance Tester Model 6472
1.1 International Electrical Symbols
Signifies that the instrument is protected by double or reinforced insulation.
This symbol on the instrument indicates a WARNING that the operator must
refer to the user manual for instructions before operating the instrument. In
this manual, the symbol preceding instructions indicates that if the instructions
are not followed, bodily injury, installation/sample and/or product damage may
result.
Risk of electric shock. The voltage at the parts marked with this symbol may be
dangerous.
Ground/Earth symbol
In conformity with WEEE 2002/96/EC
1.2 Definition of Measurement Categories
CAT IV: For measurements performed at the primary electrical supply (<1000V) such
as on primary overcurrent protection devices, ripple control units, or meters.
CAT III: For measurements performed in the building installation at the distribution level
such as on hardwired equipment in xed installation and circuit breakers.
CAT II: For measurements performed on circuits directly connected to the electrical
distribution system. Examples are measurements on household appliances or
portable tools.
1.3 Receiving Your Shipment
Upon receiving your shipment, make sure that the contents are consistent with the
packing list. Notify your distributor of any missing items. If the equipment appears
to be damaged, le a claim immediately with the carrier and notify your distributor
at once, giving a detailed description of any damage. Save the damaged packing
container to substantiate your claim.
1.4 Ordering Information
Ground Resistance Tester Model 6472.........................................Cat. #2135.51
Includes carrying bag, 110/240V power adapter with US power cord, optical USB cable,
rechargeable NiMH battery pack, and a USB stick with DataView®software, ground tester
workbook and user manual.

Ground Resistance Tester Model 6472 7
Ground Resistance Tester Model 6472 Kit (150 ft) ...................... Cat. #2135.52
Includes meter, two carrying bags, two 150 ft color-coded leads on spools (red/blue), one 30
ft lead (green), two 5 ft color-coded leads (red/blue), 110/240V power adapter with US power
cord, optical USB cable, two T-shaped auxiliary ground electrodes, set of ve spaded lugs,
one 100 ft tape measure, rechargeable NiMH battery pack, and a USB stick with DataView®
software, ground tester workbook and user manual.
Ground Resistance Tester Model 6472 Kit (300 ft) ...................... Cat. #2135.53
Includes meter, two carrying bags, two 300 ft color-coded leads on spools (red/blue), two 100
ft color-coded leads (hand-tied, green/black), two 5 ft color-coded leads (red/blue), 110/240V
power adapter with US power cord, optical USB cable, four T-shaped auxiliary ground
electrodes, set of ve spaded lugs, one 100 ft tape measure, rechargeable NiMH battery
pack, and a USB stick with DataView®software, ground tester workbook and user manual.
Ground Resistance Tester Model 6472 Kit (500 ft) ...................... Cat. #2135.54
Includes meter, two carrying bags, two 500 ft color-coded leads on spools (red/blue), two
100 ft color-coded leads (hand-tied, green/black), one 30 ft lead (green), two 5 ft color-
coded leads (red/blue), 110/240V power adapter with US power cord, optical USB cable,
four T-shaped auxiliary ground electrodes, set of ve spaded lugs, one 100 ft tape measure,
rechargeable NiMH battery pack, and a USB stick with DataView®software, ground tester
workbook and user manual.
1.4.1 Kits, Accessories and Replacement Parts
Test Kit for 3-Pole (3-Point) Testing (150 ft) .................................Cat. #2135.35
Includes two 150 ft color-coded leads on spools (red/blue), one 30 ft lead (green), two 5 ft
color-coded leads (red/blue), two T-shaped auxiliary ground electrodes, set of ve spaded
lugs, one 100 ft tape measure and carrying bag.
Test Kit for 4-Pole (4-Point) Testing (300 ft) .................................Cat. #2135.36
Includes two 300 ft color-coded leads on spools (red/blue), two 100 ft color-coded leads
(hand-tied, green/black), two 5 ft color-coded leads (red/blue), four T-shaped auxiliary ground
electrodes, set of ve spaded lugs, one 100 ft tape measure and carrying bag.
Test Kit for 4-Pole (4-Point) Testing (500 ft) .................................Cat. #2135.37
Includes two 500 ft color-coded leads on spools (red/blue), two 100 ft color-coded leads
(hand-tied, green/black), one 30 ft lead (green), two 5 ft color-coded leads (red/blue), four
T-shaped auxiliary ground electrodes, set of ve spaded lugs, one 100 ft tape measure and
carrying bag.
Test Kit for 3-Pole (3-Point) Testing
(Supplemental for 4-Pole (4-Point) Testing) .............................................Cat. #2135.38
Includes two 100 ft color-coded leads (hand-tied, green/black), one 30 ft lead (green), two
T-shaped auxiliary ground electrodes, set of ve spaded lugs, one 100 ft tape measure and
carrying bag.

8 Ground Resistance Tester Model 6472
Extra Large Classic Tool Bag ...........................................................Cat. #2133.73
Tape Measure (100 ft) ......................................................................Cat. #2130.60
Ground Tester DVD/Workbook Set...................................................Cat. #2130.64
Set of two, 14.5" T-shaped Auxiliary Ground Electrodes ..................Cat. #2135.39
Replacement - Carrying Bag for Meter.............................................Cat. #2135.40
Optical USB Cable............................................................................Cat. #2135.41
Inverter – 12V DC to 120V AC 200 Watt for vehicle use ..................Cat. #2135.43
AC Current Probe Model MN82........................................................Cat. #2135.71
AC Current Probe Model SR182 ......................................................Cat. #2135.72
Replacement - Connection Lead for Models 6472/6474*.................Cat. #2135.75
Replacement - Fuse, set of 5, 0.63A 250V 5x10 1.5kA....................Cat. #2135.81
Replacement - Calibration Loop.......................................................Cat. #2135.82
Safety Alligator Clip - Black (Rated 600V CAT IV, 10A)....................Cat. #2140.53
Safety Alligator Clip - Green (Rated 600V CAT IV, 10A) ..................Cat. #2140.69
Replacement - Battery, Rechargeable NiMH 9.6V ...........................Cat. #2960.21
Replacement - Power Adapter 110/240V & Power Cord 115V US...Cat. #5000.13
Replacement - Power Cord 115V US Plug.......................................Cat. #5000.14
*NOTE: The GroundFlex®Adapter Model 6474 is a factory supplied product only.
Order Accessories and Replacement Parts Directly Online
Check our Storefront at www.aemc.com/store for availability

Ground Resistance Tester Model 6472 9
CHAPTER 2
PRODUCT FEATURES
2.1 Description
The Ground Resistance Tester Model 6472 is a portable measurement instrument
designed to measure:
• Bond/Connection Resistance (2-Pole and 4-Pole Kelvin sensing)
• Ground Resistance (3-Pole or 4-Pole)
• Ground Coupling Resistance
• Selective Ground Resistance
• Soil Resistivity (Wenner or Schlumberger method)
• Ground Potential
• Ground Resistance with 2 clamps (no auxiliary rods)
• Ground Resistance of Pylons with the GroundFlex®Adapter Model 6474
and GroundFlex®sensors allow the system to measure leakage current and
ground resistance of tower legs without disconnecting the overhead ground
conductor.
The Model 6472 measures from 0.01 to 99.99kΩ and is auto-ranging, automatically
seeking out the optimum measurement range, test frequency and test current.
Easy-to-use - Simply connect the leads, select the test mode, press Start and read
the results. Up to 512 test results can be stored in internal memory for later recall
to the display or downloaded to a PC via DataView®software.
The large LCD is easy-to-read and indicates ground electrode resistance, test
voltage, current and frequency as well as individual electrode resistance, battery
status and more.
The Model 6472 is CAT IV rated to 50V and is over voltage protected to more than
250VAC against accidental connection to live circuits. The voltage is also displayed
on screen. In the event of a system fault, the Model 6472 can withstand 250VAC.
Additional features of the Model 6472 include a heavy-duty eld case sealed
against dust and water when closed (the test button is also sealed against the ele-
ments); manual and automatic test frequency selection from 41 to 5078Hz; user
selectable 3-Pole Fall of Potential or 4-Pole Soil Resistivity test methods and user
selectable 2-Pole or 4-Pole Bond Resistance test method.

10 Ground Resistance Tester Model 6472
The Model 6472 is powered by 9.6V, 3.5 Ah NiMH rechargeable batteries. An ex-
ternal recharger powered from 120/230V, 50/60Hz is included and provides for
testing while recharging.
The Ground Resistance Tester Model 6472 is rugged, easy-to-use and ideal for
maintenance crews performing numerous tests. It exceeds mechanical and safety
specications for shock, vibration and drop tests per IEC standards. The adjust-
able test frequency provides for rejection of high levels of interference, allowing
it to be used under di󰀩cult conditions such as high stray currents that a󰀨ect ac-
curacy.
2.2 Key Features
• Ground Resistance testing using the 2 clamp method (no auxiliary rods
needed)
• 2- and 4-Pole Bond Resistance/Continuity Measurement (DC Resistance)
with automatic polarity reversal
• 3-Pole Fall-of-Potential measurement with manual or automatic frequency
selection
• 4-Pole soil resistivity measurement with automatic calculation of Rho (ρ) and
user selection of the Wenner or Schlumberger test method
• 3-Pole earth/ground coupling measurement
• Manual and automatic frequency scan from 41 to 5078Hz for optimum test
accuracy in electrically noisy environments
• Selectable test voltage of 16 or 32V up to 250mA of test current
• Auto-o󰀨 power management
• Automatic recognition of all electrode connections and their resistance value
• Stores up to 512 complete test results in internal memory
• Optically isolated USB communication
• Remote set up and operation of all measurements using DataView®software
• Automatic report generation including the fall of potential plot
• Rechargeable NiMH batteries from wall charger or vehicle power
• Rugged dustproof and rainproof eld case – IP53 rated in closed position
• Grounding standards IEC 61557 parts 4 and 5 compliant
• Includes DataView® software for data storage, real-time display, analysis,
report generation and system conguration

Ground Resistance Tester Model 6472 11
2.3 Control Features
Ω
2 3 4
1
6
8
7
5
To Model 6474
Figure 2-1
1. Four terminals: H (Z) (auxiliary electrode), S (Y) (electrode), ES (Xv) (earth/
ground electrode) and E (X) (earth/ground electrode)
All terminals accept 4mm Ø banana plugs. Terminals H (Z) and ES (Xv) also
accept special plugs for current clamps. S (Y) will take a shielded cable.
2. Connector for charging the battery (see § 9.4).
3. 256 segment multi-line backlit LCD (see § 2.4).
4. Connector for an optical interface to a PC. Either an RS-232 or USB connec-
tion can be used (see § 8 - DataView®).
5. Connector to the GroundFlex®Adapter Model 6474 using a special adapter
cable .
6. Rotary switch: OFF position, 7 measurement functions (see § 5 and 6) and
SET-UP function (see § 4.2).
7. START/STOP button: Starts the measurement and compensates for the leads
(in the mΩ measurement function - see § 5.2.1).
8. Six function buttons - see § 2.5

12 Ground Resistance Tester Model 6472
2.4 Display
NOTE: External voltages will be displayed only on the small displays (A2 and
A3) without the view of the main display (A1). This helps to rapidly recognize
that these are measurements of external voltages.
Backlight: The backlight turns ON automatically when entering a function and
turns OFF after the function is complete. Press the DISPLAY button to turn it back
on.
NOTE: In the Set-up mode, pressing the DISPLAY button also selects the
next configurable parameter.
A1
A2
A3
Figure 2-2
A1 Top main display
A2 Middle small display
A3 Bottom small display
If this symbol blinks during a passive measurement, a voltage of more than
42V is present at the tester’s inputs.
If this symbol blinks during an active measurement, the limits of use have
been exceeded.
If the symbol appears constant during an active measurement, the values
to be measured are unstable.
Warning buzzer is activated

Ground Resistance Tester Model 6472 13
> or <
A blinking symbol > (greater than) or < (less than) indicates that the
measurement range is exceeded.
If both symbols are blinking during a passive measurement, the values of
voltage and/or current are too small and are beyond the limits of use. The
resistance RPASS displayed by the tester is then highly uncertain.
If both symbols are blinking during an active measurement, the values
to be measured are strongly varying (remedy: switch on smoothing of
measured values with SMOOTH function).
Indicates the battery charge condition; the segments represent the energy.
EARTH
COUPLING
Indicates whether the 3-Pole EARTH measurement or the EARTH COUPLING
measurement has been selected.
S x 1/10 Indicates the sensitivity of the GroundFlex®: x1/10, x1, x10.
Display of the number of turns in GroundFlex®sensors (1 to 4).
Number of GroundFlex®sensors connected (1 to 4). If this symbol blinks,
the GroundFlex®may not be connected or the current ISEL measured by
the GroundFlex®sensor is too small and is outside the limits of use.
OBJ:TEST Object and test number for storage in memory.
Indicates lead compensation for 2-Pole measurement is active
DISTANCE
If blinking, indicates the value is ready to be overwritten with a new value
or that a new value will be entered. If more than one value has to be
entered, use the CHANGE  buttons to move to the next one.
FREQUENCY Indicates the test frequency.
Indicates that the secondary function of a button will be used.
SWEEP Indicates SWEEP mode - Used in 3-Pole and 4-Pole measurements.
MANUAL Indicates MANUAL mode - the user has to stop the measurement,
otherwise the measurement keeps on running.
AUTO Indicates AUTO mode - measurement stops immediately after all results
are available.
NOISE
If blinking, indicates the measurement had a disturbance when the mea-
surement was started.
CONFIG Indicates that the blinking value of AUTO/MANUAL mode, frequency,
voltage or DC current direction can be changed.
MR Memory recall - indicates the displaying of stored results is active
MEM Indicates that there is recorded data in memory. When blinking, it indi-
cates that the results need to be saved by pressing the MEM button.
REMOTE Indicates the instrument is remotely controlled by the RS-232/USB
interface.

14 Ground Resistance Tester Model 6472
SMOOTH Indicates SMOOTHing of the displayed measurement results.
Indicates that a clamp is (steady) or should be (flashing) connected to ES.
Measured value (R, U, I).
Indicates that the measurement is running.
ALARM Indicates the alarm is activated. An audible alarm will sound if the value
measured is above the limit defined in the SET-UP mode.
Distances to be entered between earth electrode and supplementary
electrodes or between earth electrodes.
Clamp should be connected to H.
If this clamp symbol blinks, the instrument is refusing measurement
because the clamp is not connected correctly.
Symbolizes the soil resistivity value (Rho): W or S indicates that Wenner
or Schlumberger method is used for the measurement (changed by the
Hz/OPTIONS button).
2.5 Button Functions
START/STOP
Starts a measurement and compensates for lead resistance (§ 5.2.1).
Measurement stops automatically (AUTO) or is stopped by pressing this
button again (MANUAL).
Selects the second function highlighted in yellow under the buttons.
Increases or decreases the value of the flashing parameter displayed or
selects the next parameter. Press the button for a longer time to increase
the change of value speed at a faster rate.
Selects the parameter to be modified or moves the cursor to the right.
MEM/MR MEM: Stores measurements to memory.
MR: Retrieves measurements from memory.
DISPLAY/
SMOOTH
DISPLAY: Displays all parameters of a measurement.
SMOOTH: Smooths the display of measurement providing a more
stable result.
Hz/OPTIONS/
DISTANCE
Hz/OPTIONS: Enables configuration of measurement functions.
DISTANCE: Available for soil resistivity and V potential measurements. It
allows the setting of values of distances used for Rho (ρ) calculation.

Ground Resistance Tester Model 6472 15
CHAPTER 3
SPECIFICATIONS
3.1 Reference Conditions
Influencing Parameters Reference Values
Temperature 68°F ± 5.5°F (20°C ± 3°C)
Relative Humidity 45 to 55% RH
Power Supply 9 to 11.2V
Frequency Range of Input Signal 0 to 440Hz
Capacitance Parallel to Input Resistance 0 uF
Electric Field <1 V/m
Magnetic Field < 40 A/m
3.2 Electrical
3.2.1 Frequency Measurements
Measuring method: Digital with a sampling frequency of 4028Hz, low pass, FFT.
The frequency of the strongest spectral component is displayed.
Measuring rate: Display updates approx. 3 times per s.
Measurement Range 5 to 450Hz
Resolution 1Hz
Operating error ± 2Hz
Min. input voltage 10mV
Min. current through a clamp 0.5mA
Min. signal strength for GroundFlex®5mA
3.2.2 Voltage Measurements
Overvoltages up to 75Vrms are displayed as ">65V". Permanent overvoltages
between 70 and 75V at terminals H (Z) and E (X) can cause overheating of the
overvoltage protection varistor.
Voltages of more than 75Vrms lead to error message 31 (excessive external
voltage) or 32 (voltage measurement overrange).
If terminals H (Z) and E (X) are put into contact with the line voltage, the protection
fuse will blow.

16 Ground Resistance Tester Model 6472
External Voltage Measurements
Measuring Method: Digital by sampling at 4028Hz, low pass lter, FFT.
The frequency of the strongest spectral component is displayed.
Measuring Rate: Display updates approx. 3 times per s.
Signal Conversion: TRMS or sum of all harmonics 10 to 450Hz during selective
earth measurements with clamp or by GroundFlex®sensors.
Measured Range 0.00 to 9.99V 10 to 65V
Resolution 0.01V 0.1V
Intrinsic error ± (2% + 1ct)
Operating error ± (5% + 1ct)
Input impedance ZH-E, ZS-E (ZS-ES) 1.2MΩ
Operating frequency DC and 15 to 440Hz
3.2.3 Current Measurements
External Current Measurements
Measuring Method: Digital by sampling at 4028Hz, low pass lter, FFT.
Measuring Rate: Display updates approx. 3 times per s.
Signal Conversion: Sum of all harmonics 10 to 450Hz
With Current Probe SR182
Measurement Range 0.00 to
9.99mA
10.0 to
99.9mA
100 to
999mA
1.00 to
9.99A
10 to
40A
Resolution 0.01mA 0.1mA 1mA 0.01A 0.1A
Frequency range 16 to 49Hz 50 to 99Hz 100 to 400Hz
Operating error from
0.5 to 100mA ± (10% + 2cts) ± (5% + 2cts) ± (3% + 2cts)
Operating error from
0.1 to 40.0A > 20% ± (10% + 2cts) ± (5% + 2cts)

Ground Resistance Tester Model 6472 17
With Current Probe MN82
Measurement Range 0.00 to
9.99mA
10.0 to
99.9mA
100 to
999mA
1.00 to
9.99A
10 to
40A (1)
Resolution 0.01mA 0.1mA 1mA 0.01A 0.1A
Frequency range 16 to 49Hz (1) 50 to 99Hz (1) 100 to 400Hz
Operating error from
0.5 to 100mA ± (15% + 2cts) ± (7% + 2cts) ± (5% + 2cts)
Operating error from
0.1 to 40.0A > 20% ± (15% + 2cts) ± (7% + 2cts)
(1): The Model 6472 cannot detect whether a current clamp SR182 or MN82 is connected. In the case
of the MN82 clamp, with currents > 10A and frequencies < 100Hz the instrument will not display any
warning messages. It is the operator’s responsibility to observe the limits of use when using the MN82
clamp.
3.2.4 DC Resistance Measurements
Measuring Method: Voltage/Current measurement (Standard EN 61557 part 4)
Nominal Output Voltage: 16VDC (if resistance < 22Ω the output voltage is
reduced to 10VDC)
Max Output Current: > 200mADC for resistances < 20Ω
Max Overload (permanent): 50Vrms (protection up to 250V is guaranteed)
Max Inductive Load: 2 H
Max Interfering Voltage: 60Vpeak > 10Hz
Time for Auto Range Selecting: approx 5 s
Measuring Time: 8 s with automatic polarity inversion
Measuring Rate: 3 per s in manual mode
Lead Compensation: Possible from 0 to 5Ω
Alarm Setting: “>” or “<” from 1 to 999Ω(max 3 digits)
2-Pole mΩmeasurement
Measurement
Range
0.12 to
9.99Ω
10.0 to
99.9Ω
100 to
999Ω
1.00 to
9.99kΩ
10.0 to
99.9kΩ
Resolution 0.01Ω0.1Ω1Ω10Ω100Ω
Intrinsic error ± (2% + 2cts)
Operating error ± (5% + 3cts)

18 Ground Resistance Tester Model 6472
4-Pole mΩmeasurement
Measurement
Range
0.020 to
9.999Ω
10.00 to
99.99Ω
100.0 to
999.9Ω
1.000 to
9.999kΩ
10.00 to
99.99kΩ
Resolution 0.001Ω0.01Ω0.1Ω1Ω10Ω
Intrinsic error ± (2% + 2cts)
Operating error ± (5% + 5cts)
3.2.5 AC Earth Resistance Measurements
Measuring Method: Voltage/Current measurement (EN 61557 part 5)
Open circuit voltage: 16 or 32Vrms square wave (if current > 240mA the output
voltage is reduced to 10Vrms)
Test frequency: Selectable from 41 to 5078Hz (see table in § 6.2)
Short circuit current: > 200mAAC
Noise suppression: > 80 dB for frequencies 20% or more above or below the
test frequency
Max. overload: 250Vrms
Max. value for RH& RS: 100kΩ
Measuring time: Short push on START: approx. 7 s for rst value of REat
128Hz, then 3 measurements per s.
Long push on START: approx. 15 s for rst value of REat
128Hz, then 3 measurements per s.
The following error indications refer to reference conditions with a test voltage of
32V, test frequency of 128Hz, RHand RS= 1kΩ, no external voltage.
The operating error of AC resistance measurements can be less than that speci-
ed for voltage or current because frequency characteristics of the voltage channel
are matched to those of the current channel.
Measurement of auxiliary electrodes RH, RS, RES, RE
Measurement
Range
0.14 to
9.99Ω
10.0 to
99.9Ω
100 to
999Ω
1.00 to
9.99kΩ
10.0 to
99.9kΩ
Resolution 0.1Ω0.1Ω1Ω10Ω100Ω
Operating error ± (10% + 2cts)
The START button must be pressed for more than 2 s. For frequencies between
41 and 256Hz, the resistance of the auxiliary earth electrodes is measured at the
test frequency set. At higher frequencies the resistance is measured at 256Hz.