GOSSEN METRAOHM 413 User Manual

Operating Instructions

3-348-776-02

7/5.11

METRAOHM⏐413

Low impedance resistance measurement instrument

GMC-I Messtechnik GmbH
Südwestpark 15
90449 Nürnberg • Germany
Phone[phone]
Fax [phone]
E-Mail [e-mail]
www.gossenmetrawatt.com

1 –On/Off switch, see chap. 3

1

2

3

6 45

7

8

9

10

11

12

+-

!

– Auto test, see chap. 3
– Zero balancing (with key ), see chap. 4.2

2 – Zero balancing (with key ), see chap. 4.2

– Measurement (press and hold key)

3 – Polarity reversal, see chap. 4.3.2

– Query measured values, see chap. 4.3.2
– Automatic measurement mode, see chap. 4.3.3

4 LED for LO-Ω mode, measuring current 200 mA

5 LEDs + / – for polarity indication

6 LED VOLT for warning of interference voltage

7 Display for measured value and test probe polarity

as well as battery test

8 Test probe

9 Measurement cable connector

10 Measurement cable

11 Safety cap, see chap. 1 (application)

12 Snap lock, see chap. 1 (application)

Meaning of symbols on the instrument

Warning concerning a point of danger.
(Attention: observe documentation!)

Indicates EC conformity

2 GMC-I Messtechnik GmbH

Table of Contents Page

1 Application ................................................. 3

2 Safety ......................................................... 4

3 Initial Start-Up ............................................ 4

4 Measuring and Testing ..............................5

4.1 Measurement Set-Up ............................................ 5

4.2 Zero Balancing ..................................................... 5

4.3 Measuring ............................................................ 6

5 Technical Data ........................................... 9

6 Maintenance ............................................ 10

6.1 Battery ............................................................... 10

6.2 Plugs, Sockets and Contacts ............................... 10

6.3 Housing ............................................................. 10

6.4 Storage .............................................................. 10

6.5 Recalibration ...................................................... 10

6.6 Device Return and Environmentally Compatible

Disposal ............................................................. 11

7 Repair and Replacement Parts Service

Calibration Center

and Rental Instrument Service ................ 12

8 Product Support .......................................12

1 Application

METRAOHM⏐413 is a low impedance measuring

instrument with digital display for the safe testing
of cable resistances up to 2000 kΩ in electric sys­tems with nominal voltages up to 500 V.
It is designed for testing extensive protective con­ductor systems, earthing systems and potentializ­ing systems as well as shielding and lightning
protection systems.
Reliable measuring results are obtainee by the
200 mA measuring current and by the automatic
acquisition of minimum values.
Resistances between the reference earth (e.g.
equipotential bonding strip) and the measuring
points are measured by using any desired mea­surement cable (up to 3.5 Ω).
The measurement cable resistance is saved during
automatic zero balancing and taken into account
for future measurements.
In conformity with standard DIN EN 61010-031,
measurements in an environment according to
measuring category III may only be performed with
the safety cap applied to the test probe of the
measurement cable.
For establishing contact in 4 mm jacks you have to
remove the safety cap by levering out the snap
lock of the safety cap with another sharp object
(e.g. the second test probe).

GMC-I Messtechnik GmbH 3

2 Safety

You have selected a measuring instrument which
provides a high level of safety. It meets the require­ments in accordance with EN/IEC 61557-1+4
(VDE 0413 part 1+4) and EN/IEC 61010.

In order to assure safe and proper use, it is imperative
that you read these operating instructions thoroughly
and completely before placing your instrument into ser­vice.

All instructions included therein must be followed
carefully when using this instrument.

Please observe the following safety precautions:

• The measuring instrument may only be used
for power systems with an operating voltage of
maximum 500 V.

• Measurements may only be taken at voltage-
free system components.

• Only use plugs which are provided with an
insulation against accidental contact (IP 2x
with collar) for the socket of METRAOHM⏐413
when you perform measurements on locations
where voltage may be present.

• If the switched-on instrument comes into con­tact with a voltage of at least approx. 15 V, an
acoustic as well as an optical warning signal
(see chap. 4.3), are generated. In this case,
the DUT must be made voltage-free before
resistance measurements are performed.

3Initial Start-Up

The measuring instrument is delivered ready for
operation with a 9 V battery, IEC 6 LR 61. Before
initial start-up, or after a period of storage, observe
the instructions in chap. 6.

Switching On

Press key briefly (display: and green +LED).
The symbol signifies that the instrument is
ready for measurement.

Switching Off

Press key again. The instrument switches off
automatically if no key is activated for approx.
20 seconds.

Auto Test

Keep key pressed when switching the instru­ment on.
The instrument is in perfect condition when all
segments of the LCD and the 3 LEDs light up, an
acoustic signal sounds, symbol appears after
releasing the key and the green LED lights up.
If any of the displays fails, if only partly, or if readi­ness for oepration is not indicated during the auto
test, the measuring instrument may no longer be
used and must be sent in for repair.
If the error message

Fvse ERR is displayed, the

4 GMC-I Messtechnik GmbH

instrument is no longer ready for use and the over­voltage fuse must be replaced by the manufac­turer.

Battery Test

If an empty battery symbol is displayed, the bat­tery must be replaced (siehe chap. 6.1).

4 Measuring and Testing

4.1 Measurement Set-Up

Any desired measurement cable (up to approx.

3.5 Ω), which can be balanced as described in
chap. 4.2, can be used between the reference
earth (e.g. equipotential bonding strip or system
earth) and the METRAOHM⏐413. By connecting
several cables one after the other, measurement
points at distances of up to 100 m from the refer­ence earth can be reached! In environments with
strong field influences each measurement cable
should be completeley unwound so as to prevent
inductive influences.

Ð Drum with 50 m measurement cable (accessory)

Directly connect the plug of the drum with the
socket of the METRAOHM⏐413. The drum can
thus be placed onto the floor during measure­ment. Insert the contact-protected plug of the
measurement cable with test probe into the
socket of the drum. Fix the test probe at the
corresponding measuring point.

Ð 25 m reel (accessory)

Directly connect the plug of the reel with the
socket of the METRAOHM⏐413.
Fix the second plug at the corresponding

measuring point.
From time to time the plugs of the reel and the
drum must be cleaned.

4.2 Zero Balancing

The METRAOHM⏐413 must be balanced together
with the entire measurement cable prior to each
measuring series (see chap. 4.1). In this process
the resistance of the measurement cable as well
as contact resistances are stored and compen­sated for future measurements. Compensation is
done automatically for all measuring ranges with
1 μA ... 200 mA.
Manual zero balancing is also required if the same
measurement cable is re-used after some time in
order to take temperature influences into account.

Ð Affix the measurement cable to the reference

earth and ensure good contact (remove corro-

sion first if necessary!).
Ð Plug the measurement cable plug into the

socket of the METRAOHM⏐413 (with adapter

cable if reel-off drum is used).

GMC-I Messtechnik GmbH 5

Ð Switch the measuring instrument on. Press

Attention!

!

and hold key and press key in addition.
On the display, symbol
+ and Lo-Ω LEDs light up at the same time. A
progress bar appears In the top line.

Ð Apply the test probe to the reference earth, en-

suring good contact, immediately after activation of
zero balancing. Otherwise

display and the transaction is stopped.

Sequence of Electronic Zero Balancing:

• The 7 segments of the progress bar fade out
one after the other in line with the progress of
the operation, while each faded-out segment
is acknowledged by an acoustic signal.

• Polarity is reversed after half the sequence is
completed: the green – LED now lights up
instead of the green + LED, –

• The last segment of the progress bar fades
out, subsequently

• appears and the green + LED lights up:
zero balancing is completed.

Ð You may now release contact.
The measurement cable resistance is saved to
memory until a new zero balancing is conducted.
This value is preserved even if the measuring
instrument is switched off or the battery is
replaced.

If the message „Err“ (Err = Error) appears
and the measuring instrument switches
off shortly thereafter, zero balancing must
be repeated. This error occurs if the test
probe slips during balancing, or if the
cable is of high impedance (above 3.5 Ω).

Ð For test purposes we recommend that the first

measurement (see chap. 4.3) always be made
directly at the reference earth (equipotential
bonding strip or system earth) with the test
probe at the measurement cable terminal. The
result should less than 0.04 Ω for both polari­ties.

Wound up cables may cause erroneous measure­ments due to inductivities.

CAL appears and the

Err appears on the

CAL appears.

CAL disappears.

4.3 Measuring

After measurement set-up and zero balancing, the
measuring instrument is ready for operation
together with the zero-balanced cable (see chap.

4.2). Standard measurements with or without

polarity reversal as well as quick measurements
can be conducted.
Direction of current flow is indicated in the display
as + or –. The displayed sign applies to the test
probe on the measuring instrument.

6 GMC-I Messtechnik GmbH

Ð Remove corrosion or paint from the measuring

Attention!

!

+-

+-

point, if necessary.

Ð Switch on the measuring instrument: Key

appears and the green + LED lights up.

Ð Apply the measuring probe in as vertical a po-

sition as possible, ensuring good contact.

If the red LED blinks and an acoustic
warning sounds, an interference voltage is
present! The test at the selected measure­ment point must be interrupted (see chap.

4.3.4). A short warning signal can, on the
other hand, be caused by an inductive
voltage (e.g. coil not unwound) or by static
charges, which have no effect on the
measurement.

4.3.1 Standard Measurement

Ð Press key until a constant measured value

is displayed.

For measrued values below 10 Ω METRAOHM⏐413
changes automatically into the LO-Ω mode and
measures with a current of 200 mA.
In the display „Lo-Ω“ appears and the LED at the
far right signals a measuring current of 200 mA. If
the measured value is out of the measuring range
(>1999 kΩ)

4.3.2 Measurement with Polarity Reversal

It is required if galvanic voltages might affect the

0L (Overflow) blinks on the display.

measuring result.
Ð after completed measurement with positive

polarity (see above): Press key

Indication of readiness for measurement with differ­ent polarity:

and green LED –

Ð Perform the measurement with negative polar-

ity in the same manner.

Querying the Two Measured Values

Ð Request the stored positive and negative

measured value with key and compare

them.
If the values differ substantially from each other,
galvanic voltages as from approx. 15 V are proba­bly present.

Ð Repeat both measurements.
Ð If the result is the same, the mean value be-

tween + and – is to be assumed.

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4.3.3 Automatic Measurement

Note

+-+-+-

Automatic measurement is only suitable for mea­surements of resistances < 10 Ω and is always
performed with a measuring current of 200 mA
(test per VDE 0413).

Ð Activate automatic measurement mode:

Press and hold key until AuTo (automatic)
and RdY (Ready) are shown in the display, the
two polarity LEDs light up briefly.

Ð Start automatic measurement:

Press key briefly.
The measurement takes approx. 3 seconds,
polarity reversal is done automatically.

Ð To change between the two resistance values

measured with different polarities:
Press key .
The measuring results are preserved until a
new measurement is performed.

Ð Press key briefly in order to perform further

measurements.

Ð Re-activate standard measurement:

Press and hold key until AuTo disappears
from the display. As soon as RdY fades out,
standard measurements can be performed
again.

Possible errors

No measurement result is indicated.
Causes: – slipping of the test probe

–

heavily fluctuating impedances
Remedy: Repeat the measurement
Even after repeated measurement no clear mea­surement result is obtained:
Remedy: Perform standard measurement

with longer measurement dura­tions and both polarities.

4.3.4 Recognition of Interference Voltage

Applying voltage to the test probes of the measur­ing instrument in switched-on condition is sig­nalled as follows:

• The voltage value is displayed on the LCD.

•Red LED VOLT blinks, alternately, symbol

– v – appears on the LCD.

• In the case of alternating voltage, symbol ~ for

AC is also displayed.

• Additionally, an intermittent acoustic signal

sounds as a warning signal between 15 V and
400 V.

For voltages below 15 V a value is shown
which may considerably differ from the
actual voltage applied as this resistance
measuring instrument is not designed for
voltage measurement.

8 GMC-I Messtechnik GmbH

If either direct or alternating voltage is present,

Attention!

!

resistance measurement may not be performed,
until the conductor is made voltage-free.

The measuring instrument is protected by
semiconductors in the range up to 400 V,
and above that by a 500 V fuse. If the fuse
should blow, the instrument must be sent
to our repair and replacement service for
replacement (see chap. 7). The fuse is au­tomatically checked during the instru­ment’s auto testing.

5 Technical Data

Resistance measuring instrument per EN/IEC
61557-1 EN/IEC 61557-4 and EN/IEC 61010

Measuring ranges 0.01 Ω ...1999 kΩ
Accuracy
Measuring current < 10 Ω 200 mA constant

Open-circuit voltage
Digital display two-line LCD, height: 10 mm,

Voltage indication red LED, acoustic warning

Measuring category CAT II 600 V, CAT III 300 V
Overvoltage protection

Operating
temperature –10 ... +50 °C

Power supply 9 V block battery

EMC requirement DIN EN 61326
Housing Protection IP 65

Dimensions 60 mm x 230 mm x 40 mm
Weight 180 g (including battery)

±

(1.5% of rdg. + 4 digits) for 20°C

> 10 Ω 20 mA ... 1 μA
>4V

3½ places,
overflow indication by „OL“

signal, numerical display

reversible up to 400 V nomi­nal voltage by semiconduc­tors, from 400 to 500 V by
special fuse (can only be
replaced at the factory)

IEC 6 LR 61 AlMn
automatic shut-off after 20 s
without measurement,
multi-stage BAT display

impact-resistant ABS with
unbreakable display window

GMC-I Messtechnik GmbH 9

6 Maintenance

Attention!

!

6.1 Battery

A depleted battery must be removed from
the instrument. If the battery leaks the
electrolyte must be completely removed.
Dispose of batteries in accordance with
environmental regulations!

The current state of the battery is indicated by the
three-stage battery symbol in the display. When
the battery is fully charged, all three segments are
shown. If the battery symbol is half full, a large
number of measurements is still possible. If an
empty symbol is shown, the battery voltage is too
low for measuring. The battery must be replaced
by a new one. Depending on the battery type, you
can perform at least 5 more measurements in this
condition.
Attention: If the empty battery symbol blinks, the
measured values are no longer reliable. The bat­tery must be replaced immediately in this case.
The battery is located behind the cover at the rear,
which is secured with a srew.
Only 9 V block AlMn batteries, IEC 6 LR 61 should
be inserted.
Alternatively, nickel metal hydride storage batteries
(NiMH batteries) may be used. Ni-Cd batteries are
not recommended as only about 60 measure­ments can be performed due to the steep dis­charge curve and no „discharge message“ is
given.

6.2 Plugs, Sockets and Contacts

Keep them clean and free of corrosion and clean
them if necessary.

6.3 Housing

No special maintenance is required for the hous­ing. Keep outside surfaces clean. Use a slightly
dampened cloth for cleaning. Avoid the use of
cleansers, abrasives or solvents.

6.4 Storage

For lengthy periods of storage the measuring
instrument is to be stored in a dry environment
with temperatures between –10 °C and + 70 °C. It
is to be kept in a closed covering without battery.

6.5 Recalibration

The respective measuring task and the stress to
which your measuring instrument is subjected
affect the ageing of the components and may
result in deviations from the guaranteed accuracy.
If high measuring accuracy is required and the
instrument is frequently used in field applications,
combined with transport stress and great temper-

10 GMC-I Messtechnik GmbH

ature fluctuations, we recommend a relatively

Pb Cd Hg

short calibration interval of 1 year. If your measur­ing instrument is mainly used in the laboratory and
indoors without being exposed to any major cli­matic or mechanical stress, a calibration interval of
2-3 years is usually sufficient.
During recalibration* in an accredited calibration
laboratory (DIN EN ISO/IEC 17025) the deviations
of your instrument in relation to traceable stan­dards are measured and documented. The devia­tions determined in the process are used for
correction of the readings during subsequent
application.
We are pleased to perform DKD or factory calibra­tions for you in our calibration laboratory. Please
visit our website at
www.gossenmetrawatt.com (→ Services → DKD
Calibration Center or → FAQs → Calibration ques-
tions and answers).
By having your measuring instrument calibrated
regularly, you fulfill the requirements of a quality
management system per DIN EN ISO 9001.

6.6 Device Return and Environmentally Compatible Disposal

The instrument is a category 9 product (monitoring
and control instrument) in accordance with Elek­troG (German Electrical and Electronic Device
Law). This device is not subject to the RoHS direc­tive.
We identify our electrical and electronic
devices (as of August 2005) in accor­dance with WEEE 2002/96/EG and Elek­troG with the symbol shown to the right
per DIN EN 50419.
These devices may not be disposed of with the
trash. Please contact our service department
regarding the return of old devices.
I

f you use

batteries

or

rechargeable batteries

in your
instrument or accessories which no longer function
properly, they must be duly disposed of in compli­ance with the applicable national regulations.
Batteries or rechargeable batteries may contain
harmful substances or heavy metal such as lead
(PB), cadmium (CD) or mercury (Hg).
They symbol shown to the right indicates
that batteries or rechargeable batteries
may not be disposed of with the trash,
but must be delivered to collection points
specially provided for this purpose.

*

Verification of specifications or adjustment services are
not part of the calibration. For products from our facto­ry, however, any necessary adjustment is frequently
performed and the observance of the relevant specifi­cation is confirmed.

GMC-I Messtechnik GmbH 11

7 Repair and Replacement Parts Service

Edited in Germany • Subject to change without notice

• A pdf version is available on the internet

Calibration Center*
and Rental Instrument Service

When you need service, please contact:

GMC-I Service GmbH

Service Center

Thomas-Mann-Straße 20
90471 Nürnberg • Germany
Phone [phone]
Telefax [phone]
E-Mail [e-mail]
www.gmci-service.com

This address is only valid for Germany.
Please contact our representatives or subsidiaries
for service in other countries.

* Calibration Laboratory

for Electrical Quantities DKD–K –19701
accredited per DIN EN ISO/IEC 17025:2005

Accredited measured quantities: direct voltage,
direct current values, DC resistance, alternating
voltage, alternating current values, AC active
power, AC apparent power, DC power,
capacitance, frequency and temperature

Competent Partner

GMC-I Messtechnik GmbH is certified in accor­dance with DIN EN ISO 9001:2008.

Our DKD calibration laboratory is accredited by the
Deutscher Kalibrierdienst (German Calibration Ser-
vice) under registration number DKD–K–19701.

We offer a complete range of expertise in the field
of metrology: from test reports and proprietary cali-

bration certificates right on up to DKD calibration cer­tificates.

Our spectrum of offerings is rounded out with free
test equipment management.
As a full service calibration laboratory, we can cali­brate instruments from other manufacturers as
well.

8 Product Support

When you need service, please contact:

GMC-I Messtechnik GmbH

Product Support Hotline

Phone [phone]
Fax [phone]
E-Mail [e-mail]

12 GMC-I Messtechnik GmbH