Gossen MetraWatt METRISO C User manual

METRISO®C-GB int.
Insulation, Resistance and Contact Current Measuring Instrument 3-349-087-03
12/11.08
Operating Instructions

2GMC-I Messtechnik GmbH
METRISO®CMeasuring and Test Instrument METRISO®CControl Panel and Display
LIMIT U>25V
Netz
Mains
START
Operating and
Contact surface
Socket for
external charger
Keys for the selection of basic
LCD
Potentialdifference≥150Vbetween
Mainsorinterferencevoltageatmeasurementinput
Insulationvoltageatmeasurementinput>2
5V
Limitvalueviolation
Left switch contact:
Displays basic functions,
Toggle Switch
Middle switch contact:
Starts measurement
functions and sub-functions,
Right switch contact:
Displays basic functions,
scrolling from right to left scrolling from left to right
Battery level display
fingercontactandmeasurementinput
Indicator lamps
Shield
jack
Measurement
jack, COM
Meas. jack + pole
article no. Z501N
(menu-driven operation)
The desired measuring
functions can be dis-
played with the help of
the and keys.
The scroll bar indicates which
menu is currently open.
Fuse
Carryingstrap
Closure
display unit
Infrared interface Temperature and
humidity measuring adapter
Z541A

GMC-I Messtechnik GmbH 3
LCD after Switching on the Instrument
Please proceed as follows if the LCD display is not legible, i.e. too bright
or too dark, after switching on the test instrument:
1 Simultaneously press the two right-hand keys to delete the memory
which might be faulty.
2 Wait a few seconds to allow the display to be updated.
3 Readjust the contrast if necessary, see page 8.
Instructions for the Plug-on of the Following Accessory Adapters
• Interface converter IrDa-USB (Z501J)
• Temperature and humidity measuring adapter (Z541A)
➭Connect the adapter with the IR interface of the test instrument, see
drawing on page 2: Insert the guide rail of the adapter in the opening
provided on top of the tester so that the adapter is located in the mid-
dle of the housing, resting on the two rubber cushions. Then push the
adapter down to ensure that it is safely fastened.
PC software WinProfi for communication with METRISO®C
The PS3 CD-ROM includes the software WinProfi with the following con-
tent and functions:
• up-to-date test instrument software
– for loading another language
– for loading software version updates,
• Exchange of measured data between test instrument and PC
• Preparation, print-out and filing of test reports at the PC
The following interface converter is required for communication between
test instrument and PC:
– IrDa-USB Converter (Z501J): IrDa (tester) – USB (PC)
Data Backup
Measurement data and electrical circuit assignments can be safely stored
in a RAM as long as the associated battery supplies the required voltage.
We advise you to regularly transmit your stored data to a PC in order to
prevent potential loss of data in the test instrument. We assume no
responsibility for any data loss.
For data processing and management we recommend the following PC
software programs:
• PS3 (documentation, management, report generation and
monitoring of deadlines)
• PC.doc-WORD/EXCEL (report and list generation)
• PC.doc-ACCESS (test data management)
+

4GMC-I Messtechnik GmbH
Contents Page Contents Page
1 Applications .....................................................................................5
2 Safety Features and Precautions ....................................................5
3 Initial Start-Up .................................................................................6
3.1 Battery Test ....................................................................................................6
3.2 Installing and Replacing Batteries .....................................................................6
3.3 User Guide in a Different Language ..................................................................6
3.4 Selecting a Menu and Configuring Basic Settings ..........................................6
3.5 Downloading a Software Update, Managing Report Data ...................................9
4 General Operation .........................................................................12
4.1 Automatic Settings, Monitoring and Shutdown ................................................12
4.2 Measurement Value Display ..........................................................................12
4.3 Online Help ...................................................................................................12
5 Measuring Insulation Resistance ..................................................13
5.1 Insulation Measurement with Adjustable Test Voltage ......................................14
5.2 Measurement with Rising Test Current ...........................................................14
5.3 Setting the Limit Value ..................................................................................14
6 Database Functions .......................................................................15
6.1 Creating a Data Record – Data Function .........................................................15
6.2 Saving Measurement Values – STORE Function ..............................................16
6.3 Querying Data Records – View Function .........................................................16
6.3.1 Deleting a Data Record from within a Memory Address – View Function ...........17
6.3.2 Deleting a Memory Address – Data Function ..................................................17
6.3.3 Delete All Memory Addresses – Data Function ................................................18
6.4 Print Function ...............................................................................................18
7 Measuring Alternating Voltage ......................................................19
8 Measuring Temperature and Humidity with Adapter Z541A
(Accessory Adapter) ......................................................................19
9 Measuring Low-Value Resistance (to 100 Ω) ................................20
9.1 Compensation for Measurement and Extension Cables (up to 10 Ω) .................21
9.2 Setting the Limit Value .................................................................................. 21
10 Measuring Contact Current ...........................................................22
10.1 Setting the Limit Value .................................................................................. 22
11 Characteristic Values ....................................................................23
12 List of Abbreviations and their Meanings .....................................25
13 Maintenance .................................................................................25
13.1 Self-Test .................................................................................................. 25
13.2 Battery Operation ......................................................................................... 26
13.3 Changing the Batteries of the Temperature and Humidity Measuring
Adapter Z541A ............................................................................................ 26
13.4 Fuses .......................................................................................................... 26
13.5 Housing ....................................................................................................... 27
14 Repair and Replacement Parts Service
DKD Calibration Center* and Rental Instruments Service .............27
15 Product Support ............................................................................28

GMC-I Messtechnik GmbH 5
1 Applications
This instrument fulfills the requirements of the applicable European and
national EC guidelines. We confirm this with the CE marking. The relevant dec-
laration of conformity can be obtained from GMC-I Messtechnik GmbH.
The METRISO®C test instrument allows for quick and efficient testing of
protective measures in accordance with DIN VDE 0100, ÖVE-EN 1 (Aus-
tria), SEV 3755 (Switzerland) and other country specific regulations. The
instrument is equipped with a microprocessor and complies with IEC/
EN 61557/VDE 0413.
Part 1: General requirements
Part 2: Insulation resistance measuring instruments
Part 4: Measuring instruments for the measurement of resistance at
earth conductors, protective conductors and bonding
conductors
as well as requirements in accordance with VDE 0701-0702:
Repair, modification and testing of electrical devices
The test instrument is especially well suited for:
• Systems installation
• Initial start-up
• Periodic testing
• Troubleshooting in electrical systems
All required measurements can be performed for approval reports (e.g. for
ZVEH) with the help of a set consisting of the PROFiTEST®Cand the
METRISO®C.
Measurement values can be transmitted to a PC for printing and archiving
via the integrated IR data interface at the METRISO®C. This is especially
important where product liability is concerned.
The following measurements and tests can be performed with the METRISO®C:
• Insulation resistance
• Low-value resistance
• Contact current
• Voltage and frequency
• Temperature and humidity (with accessories)
The following can also be measured with a shielded measurement cable:
• Conductivity of floor coverings for electrostatic discharge
2 Safety Features and Precautions
The METRISO®Celectronic measuring and test instrument is manufac-
tured and tested in accordance with safety regulations IEC/EN 61010-1/
VDE 0411-1 and EN 61557. If used for its intended purpose, the safety of
the operator and the instrument is assured.
Read the operating instructions carefully and thoroughly before using your
instrument, and observe all instructions included therein.
The measuring and test instrument may not be used:
• If the battery compartment cover has been removed
• If external damage is apparent
• With damaged connector cables or measuring adapters
• If it no longer functions flawlessly
• After excessive stress due to transport
• After lengthy periods of storage under unfavorable conditions
(e.g. humidity, dust, extreme temperatures)
• While the batteries are being charged
Meanings of Symbols on the Instrument
Warning concerning a point of danger
(Attention: observe documentation!)
Protection class II device
CAT II Measuring category I I device
9 V DC charging socket for NA102 charging adapter
(
part no. Z5 01N)
Approval mark by VDE test authority
Indicates EC conformity
This device may not be disposed of with the trash. Further informa-
tion regarding the WEEE mark can be accessed on the Internet at
www.gossenmetrawatt.com under the search term ’WEEE’ .
!
–

6GMC-I Messtechnik GmbH
3 Initial Start-Up
3.1 Battery Test
Five battery symbol segments ranging from depleted to fully charged
continuously indicate the current battery level at the main menu.
3.2 Installing and Replacing Batteries
New batteries must be installed before initial start-up, or when only one
solid segment remains in the battery symbol.
Attention!
!
The instrument must be disconnected from the measuring circuit
(mains) at all poles before the battery compartment is opened.
Four 1.5 V baby cells in accordance with IEC LR14 are required for
operation of the METRISO®C. Use alkaline-manganese batteries only.
Rechargeable NiCd or NiMH batteries can be used as well. Be absolutely
sure to refer to chapter 13.2, page 26, regarding the charging cycle and
the charging adapter.
Always replace the batteries in complete sets.
Dispose of batteries in an environmentally sound fashion.
➭Loosen the two slotted screws at the battery compartment cover on
the housing rear panel and remove the cover.
➭Insert four 1.5 V baby cells making certain they are poled in
accordance with the symbols. Insert the two batteries which are half
covered by the housing first.
➭Replace the cover and retighten the screws.
Attention!
!
The instrument may not be operated if the battery compartment
cover has not been installed and properly tightened!
3.3 User Guide in a Different Language
By performing a software update it is possible to load another language
for the user guide than the one included in the scope of supplies. Any lan-
guage currently available is proposed for choice when WinProfi is being
installed, see chapter 3.5.
3.4 Selecting a Menu and Configuring Basic Settings
Press the or the key in order to display the desired measuring
function, the device settings or the database functions.
START
START

GMC-I Messtechnik GmbH 7
Default Settings – Last Used Settings
A selection can be made here as to whether the menus will be displayed
according to the default settings, or if the last opened menus should be
displayed.
➭Activate the Setup key.
➭Press the Default key, if required:
on ✓Settings such as Ton (= 20sec) are reset to the default settings
each time the instrument is switched on.
off ✓The last used settings remain when the instrument is switched
on.
➭Press the key to quit the setup menue.
Setting On-Time, Manual Shutdown
➭Activate the Setup key.
➭Press the Ton key and then the 10sec, 20sec, 30sec or 60sec key depend-
ing upon the desired duration after which the test instrument should
switch off automatically. Additional setting options can be displayed
with the help of the and scroll keys.
The “>>>>>” setting indicates that no automatic shutdown will occur.
The selected setting has a considerable influence on battery service
life.
➭Press the key to quit the setup menue.
The instrument can be switched off manually by simultaneously activating the two
outermost softkeys.

8GMC-I Messtechnik GmbH
Background Illumination and Contrast
➭Activate the Display key.
➭In order to extend battery service life, display illumination can be
switched off entirely.
Press the corresponding softkey to this end.
If LCD illumination is activated (= ON), it is automatically switched off
several seconds after the last key has been activated in order to extend
battery service life. As soon as a key is activated again, illumination is
switched back on.
➭Contrast can be optimized with the two keys at the far right.
➭Press the START key to quit the setup menue. The data are saved to
memory.
Setting the Clock
➭Activate the Time key.
➭The cursor appears at the first digit in the date. Enter the desired
numeral with one of the softkeys.
Numerals which do not appear in the window can be displayed with
the help of the or the key. Each time a numeral is selected,
the cursor moves to the next position to the right.
➭Date and time are saved as soon as the last numeral has been
entered.
➭Press the START key to quit the setup menue. The data are saved to
memory.
low high
Contrast
off on
LCD Illumination

GMC-I Messtechnik GmbH 9
3.5 Downloading a Software Update, Managing Report Data
If you require an updated test instrument software, it can be downloaded
with the help of WinProfi PC software. The data file with the desired soft-
ware version is transmitted to the test instrument via the serial interface.
The previously installed language is overwritten.
Note
☞
This software includes all of the functions required for communica-
tions between the METRISO®Cand the PC. A description of the
program is included in the online user’s manual which can be
accessed from WinProfi.
Programm WinProfi
A Install WinProfi to the PC and Start the Program
➭First install the software to your PC.
Insert the CD into the CD drive, for example drive E.
Execute the file E:\GMCDEMO
➭Click the globe icon.
➭Follow the instructions which appear at the monitor.
The program is added to your START menu after installation.
➭Establish a connection between your PC and the
PROFiTEST®0100S-II test instrument by using interface converter
IrDa-USB.
➭Start WinProfi.
➭Switch on the test instrument.
➭Set the on-time period of the METRISO®Cto „>>>>>“, to give you
enough time for adjusting the settings in WinProfi before the test in-
strument switches off again automatically, see chapter 3.3.
Display or print out online user’s manual
The online manual contains information concerning the software which is
not included in these operating instructions.

10 GMC-I Messtechnik GmbH
B Prerequisites for Software Update or Data Exchange
➭Find the interface to which the METRISO®Cis connected.
Note
☞
Always start this function first, before performing an update or chang-
ing report templates. After starting this function, WinProfi loads the
report files specifically necessary for the connected instrument.
Due to the fact that WinProfi has been created for use with several
types of test instruments, incorrect test reports may otherwise be
loaded, or erroneous options may be made available.
➭Query information regarding current software version
C Transmission of a Software Update to the Test Instrument
➭PC: Select the Update All function from the Update menu. Follow the
instructions which appear at the monitor.
Depending upon the utilized PC, transmission takes from 1 to 2 minutes.
The NETZ/MAINS LED of the METRISO
®
Ctest instrument lights up green and indicates
that the instrument is ready to receive data. If the PC and the test instrument are correctly
synchronized, the same LED lights up yellow. During programming sequences, the LIMIT
and U>25V LEDs light up red and the NETZ/MAINS LED lights up yellow in alternating
order. Upon completion of data transmission, the NETZ/MAINS LED briefly lights up green,
afterwards all LEDs go out.
The message „Transmission done“ appears on the computer screen
Attention!
!
The instrument may not, under any circumstances, be switched
off during transmission, nor may the connection between the in-
strument and the PC be interrupted!

GMC-I Messtechnik GmbH 11
D Managing Report Data
➭Connect the METRISO®Ctest instrument with your PC via the IrDa-
USB converter
➭Start WinProfi.
➭Switch on the test instrument.
➭Set the on-time period of the METRISO®Cto „>>>>>“, to give you
enough time for adjusting the settings in WinProfi before the test in-
strument switches off again automatically, see chapter 3.3.
• Send or receive a data file
•Printdata
• Edit or transmit report templates
6
3
5
2
1
4

12 GMC-I Messtechnik GmbH
4 General Operation
The test cables are connected to the “+” and “COM” jacks.
The shielded cable should also be connected to
the COM and SHIELD jacks for the measurement of
electrostatic discharge capacity at floor cover-
ings. (Accessory equipment KS-C „Cable set
consisting of measurement cable and high-resis-
tance measurement cable for METRISO C, for
measurements in the GΩrange“, see connection
diagram). Observe color codes when connecting
the cables!
4.1 Automatic Settings, Monitoring and Shutdown
The instrument cannot be placed into operation, or it is shut down auto-
matically, if battery voltage has fallen to below the lower limit value.
Measurement is automatically interrupted and/or the measuring function
is disabled if voltage exceeds the allowable limit in the resistance range
(U > 25 V).
The instrument switches itself off automatically, at the earliest after the
current (automatic) measuring sequence has been completed, and after
the predefined on-time has elapsed (see chapter 3.4). On-time is reset to
the duration selected in the setup menu each time a key is activated.
Lamp Functions
4.2 Measurement Value Display
The following is displayed at the LCD:
• Measurement values with abbreviated quantity type and units of
measure
• The selected function
When automatic measuring sequences are used, the measurement
values are displayed in digital format until the next measuring sequence is
started, or until the instrument switches itself off automatically.
If the measuring range upper value is exceeded, the upper value is dis-
played preceded by the greater than symbol “>” in order to indicate over-
ranging.
4.3 Online Help
Appropriate online help texts can be displayed at the LCD for each of the
basic functions and sub-functions, after the respective function has been
selected in the corresponding menu.
➭Press the key to query online help.
Press any key to exit the help function.
Lamp Status Function
red Potential difference ≥150 V
between finger contact and measurement input
Netz
Mains blinking red
Line voltage or interference voltage is present at the measurement inputs
(insulation resistance and low resistance measurement are disabled)
LIMIT red
– Measured insulation resistance is less than the selected limit
value.
– The measured low-value resistance is less than the allowable
limit value.
U>25V red
A voltage of greater than 25 V is present at the measurement
inputs.
The discharging process is not yet complete.
COM
SHIELD
+
KS-C
(Z541F)
i

GMC-I Messtechnik GmbH 13
5 Measuring Insulation Resistance
Insulation resistance can only be measured at voltage-free objects. If
mains voltage or an interference voltage is applied to the measurement
cables, insulation resistance is not measured and the Netz/Mains lamp
lights up.
Note
☞
Testing of Measurement Cables
We recommend short-circuiting the measurement cables with the
test probes before carrying out the insulation measurement to
check whether the instrument indicates almost zero W (see chap-
ter 9). This helps to discover interruptions in the measurement
cables which simulates a high insulation resistance.
➭Press the RISO key.
The currently selected test voltage (nominal voltage) is displayed between
RISO and UISO.
➭Select another test voltage if necessary by pressing UISO and then the
desired test voltage.
➭Connect the device under test to the +and COM jacks.
➭Start the measurement by pressing the START key.
Attention!
!
Do not touch the connector terminals at the instrument during
performance of insulation resistance measurement!
Note
☞
Three-Phase Current Systems
All conductors (L1, L2, L3 and N) must be measured against PE!
If the connector terminals are free, or if they have been connected to an
ohmic power consumer for the performance of a measurement, a current
with a value of approximately 1 mA would flow over your body at a voltage
of 1000 V.
This electrical shock is not life endangering. However, the plainly
perceptible shock may result in injury (as a result of startling etc.).
Capacitive Devices Under Test
Attention!
!
If measurement is performed at a capacitive object, e.g. a long
cable, it is charged to a level of as great as 1000 V!
In this case, contact with the object is life-endangering!
After completion of insulation resistance measurement at capacitive
objects, the device under test is automatically discharged via the
instrument after the START key has been released. Contact with the object
must therefore be maintained.
Do not disconnect the device under test until UISO < 25 V appears at the display.
Note
☞
The instrument’s batteries are depleted rapidly during the
measurement of insulation resistance. Only hold the START key
depressed until the display value has stabilized.

14 GMC-I Messtechnik GmbH
5.1 Insulation Measurement with Adjustable Test Voltage
A DC test voltage within a range of 50 to 1000 V can be selected with the
UVAR function for measurements at sensitive components and in
systems equipped with voltage limiting components.
➭Select the UVAR function from the UISO menu with the or the
key and acknowledge with the UVAR key.
➭In order to enter the desired value:
Display the desired numerals, and if required the decimal point, with
the help of the and keys. Select the desired numerals with
the appropriate softkeys. Each time an entry is made, the cursor
moves one place to the right. After a maximum of three numerals
have been entered, exit the data entry window by pressing the →soft-
key. If the selected voltage is not within the valid range, the cursor
jumps back to the entry position for the first digit.
After the value has been completely entered and acknowledged with
the START key, UVAR is displayed between RISO and UISO.
➭The remainder of the measurement procedure is identical to the test
sequence used for predefined nominal voltages.
5.2 Measurement with Rising Test Current
The “U ” function can be used for the detection of weak points in
insulation, as well as for the determination of response voltage at voltage
limiting devices.
➭Select the U function from the UISO menu with the or the
key and acknowledge with the U key.
As long as the START key is depressed, test voltage is continuously
increased. Insulation measurement begins:
• As soon as maximum voltage is reached (= variable test voltage, see
chapter 5.1) or
• As soon as the START key is released
(when the desired voltage appears at the display) or
• As soon as a measurable test current is detected (e.g. after a
discharge voltage sparkover).
Test voltage, any response or discharge voltages values and insulation
resistance are all displayed.
5.3 Setting the Limit Value
A limit value for insulation resistance can be selected with the LIMIT key. If
measured values are detected below the limit value, the red LIMIT LED
lights up.
START
START

GMC-I Messtechnik GmbH 15
6 Database Functions
The displayed measurement data for each measurement can be saved to
an internal database, with or without a comment. A data record must be
created and allocated to a specific memory address in order to be able to
assign the individual measurement values to different buildings, distribu-
tion cabinets and measuring circuits.
6.1 Creating a Data Record – Data Function
➭Press the Data key.
➭First create the desired memory address with the help of the softkeys.
After acknowledging with the START key (press at center), the cursor
appears at the first data entry position (BUILDING).
➭With the help of the softkeys, entries can be made to the BUILDING,
DISTRIBUTOR CABINET, RCD No. and CIRCUIT fields one after the other, and
a designation can be entered for the electrical circuit.
Entering Data:
Display the desired alphanumeric character by pressing the or
the key, and then select the character with the corresponding
softkey.
Control characters can be entered in the same way and have the fol-
lowing meanings:
←: Move cursor to the left (without deleting data)
→: Move cursor to the right (without deleting data)
↵:Same function as the START key
After each character is selected, the cursor moves one position to the
right. If ↵or the START key is activated (press at center), the cursor
moves to the next entry field. After the fields BUILDING, DISTRIBUTOR
CABINET, RCD No. and CIRCUIT have been completed, and after acknowl-
edgement has been confirmed with the ↵softkey, the data fields are
displayed as inverse images. After the ↵softkey has been activated
once again, a designation for the selected electrical circuit can be en-
tered.
Note
☞
These entries are required by the PC software in order to enter
measurement values into the database, and to generate reports
with this information automatically.

16 GMC-I Messtechnik GmbH
6.2 Saving Measurement Values – STORE Function
➭Start the respective measurement. The STORE key is displayed after
the measurement instead of the INFO key.
The STORE key is not displayed until after a given amount of time has
elapsed for measurements which are performed without the START
key. For example, the store key is not displayed after voltage
measurements until a given amount of time has elapsed, so that the
operator can first query the help text with the INFO key.
➭The displayed measurement values are stored to the currently
selected database memory address by briefly acknowledging with
the STORE key. The key is briefly displayed as an inverse image during
storage to memory.
➭Pressing and holding the STORE key allows for the entry of a comment,
and storage of the current measurement.
Entering a comment:
Display the desired alphanumeric character with the or the
key and select the desired character with the corresponding softkey.
Control characters are entered in the same way and have the
following meanings:
←: reverse and delete,
↵:same as the START key
After each character has been selected, the cursor moves one posi-
tion to the right. Already entered characters can be deleted in reverse
by pressing and holding any softkey (except for ↵).
After entry of up to 15 characters, save the measurement values and
the comment by acknowledging with the START key (press at center) .
The following message appears: “Data are stored”.
Note
☞
The test reports included with the analysis software (e.g. PS3)
have separate fields for measured values RISON (without load) and
RISOL (with load). Enter an “N” as the first character for measure-
ment of RISON (i.e. without load), so that the analysis software is
able to determine which value is to be stored for the report.
Otherwise, measured values are automatically stored as RISOL, i.e.
with load.
6.3 Querying Data Records – View Function
➭Select View.
➭You can scroll forward through the memory addresses with the
key, or backwards with the key.
➭After selecting a memory address, the individual data records can be
queried with the Prev. and Next softkeys, which have been stored to
memory under consecutive numbers.
START
START

GMC-I Messtechnik GmbH 17
In case a measurement value is missing for the currently selected current
circuit, perform the measurement and the value will be immediately
stored.
6.3.1 Deleting a Data Record from within a Memory Address – View Function
➭Activate the Del key. No security request appears.
Data record numbering is changed as soon as an individual data
record is deleted.
6.3.2 Deleting a Memory Address – Data Function
➭Select Data.
➭Enter blanks to the data fields BUILDING, DISTRIBUTOR CABINET,RCD No.
and CIRCUIT. After all of these fields have been entirely overwritten with
blanks,they are displayed as inverse images.
➭Acknowledge with the START key (press at center). All data from the
selected memory address are deleted.
START

18 GMC-I Messtechnik GmbH
6.3.3 Delete All Memory Addresses – Data Function
Up to 250 data records can be stored to memory. The memory is full
when the bar graph to the right of “MEMORY:” is entirely filled in. The entire
memory, i.e. all data records from all memory addresses, can be deleted
at once. We recommend uploading and saving your data to a PC before
deletion.
➭Select Data.
➭Enter memory address “000”. After acknowledgement by pressing
button START (press at center) a safety request appears.
➭By simultaneously activating O and K all data that have been saved
are deleted from memory. The bar graph to the right of the parameter
„MEMORY:“ is empty. To the left, memory address „001“ is displayed.
New data can now be entered for the first address, or the
database can be exited (press ↵or START 9 times).
If the above message appears upon switching on the test instrument, all
data can be saved to a PC before finally deleting the database in order to
rectify the error.
6.4 Print Function
Functions the symbols of which appear in gray or are displayed only in a
faint raster screen, will not be available until after the next software
update.
3x
+
+

GMC-I Messtechnik GmbH 19
7 Measuring Alternating Voltage
Sinusoidal alternating voltage within a frequency range of 40 to 200 Hz
can be measured with the test instrument.
➭Press the U~/f key.
➭Contact the measuring points with the measuring probes.
Note
☞
The input impedance for the voltage measuring range is 5 MΩ.
8 Measuring Temperature and Humidity with Adapter Z541A
(Accessory Adapter)
Temperatures within a range of –10.0 °C to +50.0 °C, as well as relative
humidity from 10.0% to 90.0% can be measured with the temperature-
humidity combination adapter.
➭Connect the temperature-humidity adapter to the IR interface of the
test instrument (see drawing on page 2) by inserting the guide pin of
the adapter in the opening provided at the top of the test instrument
such that the adapter is located on the two rubber pads in central
position to the housing. Then push the adapter down to fix it tightly.
➭Press the T/FRELkey. The adapter is activated via the interface.
➭Select the desired temperature unit of measure, °C or °F, wit h the
corresponding key. Temperature and humidity are displayed directly.
➭We recommend moving the test instrument with the adapter to and
fro for a few seconds to enable the adapter to adjust to the prevailing
room climate more quickly. The air current can thus penetrate through
the opening into the adapter housing more quickly. It would otherwise
take several minutes to achieve this condition.
➭When changing to another function, the adapter is deactivated.
➭The measured values are only updated every 5 seconds to spare the
adapter batteries.
Display at the Test Instrument
The „———“ symbol shown on the display can be attributed to the fol-
lowing causes:
– incidence of sunlight
– depleted batteries in adapter Z541A
– adapter defective or not properly positioned
Adapter Z541A should not be exposed to intensive sunlight to prevent
inadvertent activation via infrared (battery life!).

20 GMC-I Messtechnik GmbH
9 Measuring Low-Value Resistance (to 100 Ω)
According to the regulations, measurement of low-value resistance at
protective conductors, earth conductors and bonding conductors must
be performed with (automatic) measuring voltage polarity reversal, or with
the flow of current in one direction (+ pole to PE), or the other (– pole to
PE).
Attention!
!
Low-value resistance may only be measured at voltage-free
objects.
Attention!
!
In order to be able to start the measurement, contact must first be
established between the test probes and the device under test.
If voltage is present at the device under test, or if resistance is greater
than 100 Ω, no measurement is performed.
Automatic Polarity Reversal – AUTO± Function
With automatic polarity reversal, the instrument performs measurement
first in one direction and then in the other, after the measuring sequence
has been started.
The largest measured resistance value is always displayed. This
presupposes that AUTO±is displayed underneath RLO. If either of
the values RLO/+ or RLO/– is displayed instead of AUTO±, press
the +/−key in the menu bar and then AUTO±.
Resistance values which do not demonstrate stabilized values until after
settling in, should not be measured with automatic polarity reversal.
Measurement with automatic polarity reversal may result in varying,
excessively high measured values and thus to an ambiguous read-out.
Measurement with + Pole to PE, or – Pole to PE
In order to determine whether or not test results are independent of the
direction of flow, measurement can be performed separately in both
directions. Press the +/−key in the menu bar to this end, and then either +
or – depending upon the desired direction of flow.
Differing results indicate that voltage is present at the device under test
(e.g. thermoelectromotive force or elemental voltage).
Measurement results may be distorted by parallel connected impedances
from load current circuits and equalizing current, especially in systems
equipped with “overcurrent protective devices” (formerly neutralization)
without a separate protective conductor. A change in resistance during
measurement (e.g. inductance), or poor contact may also result in
distorted measurements.
The following are examples of resistance values which may change during
measurement :
– Resistance values for incandescent light bulbs due to warming
caused by test current
– Resistance with an excessively high inductive component
In order to assure unambiguous measurement results, it is necessary to
recognize and eliminate any cause of error.
The instrument’s batteries are depleted rapidly during resistance
measurement. Only press the START key as long as necessary during
measurement with current flow in a single direction.
START