Gossen MetraWatt METRAHIT ISO User manual

METRAHITISO
TRMS Multimeter with Insulation Measurement
Operating Instructions
3-349-416-03
9/4.12

2GMC-I Messtechnik GmbH
Standard Equipment Contact Persons
Standard Equipment
1 Multimeter for isolation measurement
1 protective rubber cover
1 KS17-2 cable set
1 condensed operating instructions, English/German
1 operating instructions in English and German
(CD ROM or printed)
1 DKD calibration certificate with calibration report
2 batteries, 1.5 V, type AA, installed
1) For 15,400 measured values, sampling rate adjustable from 0.1 second to 9 hours
Function METRAHITISO
V AC+DC TRMS (Ri = 1 M  )

V AC / Hz TRMS (Ri  9 M  )

Filter
V AC+DC TRMS (Ri
 9 M  )

V DC (Ri 9 M)
Hz (V AC) ... 300 kHz
Bandwidth V AC 15 Hz ... 10 kHz
A AC / Hz TRMS 300 A
3/30/300 mA
3 A / 10 A
A AC+DC TRMS
A DC
Fuse 10 A/1000 V
Transformation factor mV/A, mA/A
Hz (A AC) ... 30 kHz
Insulation Resistance MISO adjustable test voltage
Resistance 
Continuity 
Diode ... 5,1 V 
Temp erature TC (K) 
Temperature RTD

Capacitance 
MIN/MAX / data hold 
4 MBit memory 1) 
IR Interface 
Power pack adapter socket 
Protection IP54
Measuring category 1000 V CAT II, 600 V CAT II I
1kHz

GMC-I Messtechnik GmbH 3
Contact Persons
Accessories (sensors, plug inserts, adapters, consumable materials)
The accessories available for your instrument are checked for
compliance with currently valid safety regulations at regular
intervals, and are amended as required for new applications.
Currently up-to-date accessories which are suitable for your mea-
suring instrument are listed at the following web address along
with photo, order number, description and, depending upon the
scope of the respective accessory, data sheet and
operating instructions:
www.gossenmetrawatt.com
See also chapter 10 on page 66.
Product Support
Technical Queries
(use, operation, software registration)
If required please contact:
GMC-I Messtechnik GmbH
Product Support Hotline
Phone: [phone]
Fax: [phone]
E-mail [email protected]
Software Enabling for METRAwin 10
GMC-I Messtechnik GmbH
Front Office
Phone: [phone]
Fax: [phone]
E-mail: [email protected]
Training
Training in Nuremberg, on-site training at customer facilities
(scheduling, prices, registration, travel, accommodation)
If required please contact:
GMC-I Messtechnik GmbH
Training Division
Phone: [phone]
Fax: [phone]
E-mail: [e-mail]

4GMC-I Messtechnik GmbH
Standard Equipment Contact Persons
Recalibration Service
We calibrate and recalibrate all instruments supplied by GMC-I
Messtechnik GmbH, as well as other manufacturers, at our ser-
vice center, for example after one year within the framework of
your test equipment monitoring program, as well as prior to use
etc. and offer you test equipment management free of charge.
See also chapter 9.6 on page 65.
Repair and Replacement Parts Service
Calibration Center* and Rental Instrument Service
If required please contact:
GMC-I Service GmbH
Service Center
Thomas-Mann-Str. 16-20
90471 Nuremberg, Germany
Phone: [phone]
Fax: [phone]
E-mail [e-mail]
www.gmci-service.com
This address is only valid in Germany. Please contact our
representatives or subsidiaries for service in other countries.
* Calibration Laboratory for Measured Electrical Quantities
DKD – K – 19701 accredited per DIN EN ISO/IEC 17025:2005
Accredited quantities: direct voltage, direct current value, direct current
resistance, alternating voltage, alternating current value, AC active
power, AC apparent power, DC power, capacitance, frequency,
temperature

GMC-I Messtechnik GmbH 5
Contact Persons
Competent Partner
GMC-I Messtechnik GmbH is certified in accordance with
DIN EN ISO 9001:2008.
Our DKD calibration lab is accredited by the Physikalisch-
Technischen Bundesanstalt (German Federal Institute of Physics
and Metrology) and the Deutscher Kalibrierdienst (German
Calibration Service) in accordance with DIN EN ISO/
IEC 17025:2005 under registration number DKD–K–19701.
We offer a complete range of expertise in the field of metrology:
from test reports and factory calibration 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 lab, we can calibrate instruments from
other manufacturers as well.

6GMC-I Messtechnik GmbH
Table of Contents
Contents Page Contents Page
1 Safety Features and Precautions ....................................... 8
1.1 Use for Intended Purpose ................................................................10
1.2 Meanings of Danger Symbols ..........................................................10
1.3 Meanings of Acoustic Warning Signals ............................................10
2 Operating Overview – Connections, Keys, Rotary Switch, Symbols 12
3 Initial Start-Up .................................................................. 16
3.1 Batteries ........................................................................................16
3.2 Activation .......................................................................................16
3.3 Setting the Operating Parameters ....................................................16
3.4 Switching the Instrument Off ...........................................................17
4 Control Functions ............................................................. 18
4.1 Selecting Measuring Functions and Measuring Ranges .....................18
4.1.1 Automatic Range Selection .............................................................18
4.1.2 Manual Measuring Range Selection .................................................18
4.1.3 Quick Measurements ......................................................................19
4.2 Zero Offset / Relative Measurements ...............................................19
4.3 Display (LCD) .................................................................................20
4.3.1 Digital Display ................................................................................20
4.3.2 Analog Display ...............................................................................20
4.4 Measured Value Storage: DATA (auto-hold / compare) ......................21
4.4.1 Function DATA during insulation measurement * ..............................22
4.4.2 Saving Minimum and Maximum Values – MIN/MAX Function ............23
4.5 Measurement Data Recording .........................................................24
5 Measurements ................................................................. 26
5.1 Voltage Measurement ....................................................................26
5.1.1 Direct and Pulsating Voltage Measurement, V DC and V (DC+AC) .....27
5.1.2 Alternating Voltage and Frequency Measurement V AC and Hz
with Selectable Low-Pass Filter .......................................................28
5.1.3 Transient Overvoltages ...................................................................31
5.1.4 Voltage Measurements at Above 1000 V .........................................31
5.2 Resistance Measurement, 
5.3 Temperature Measurement: Temp RTD and Temp TC ......................33
5.3.1 Measurement with Resistance Thermometers ..................................33
5.3.2 Measurement with Thermocouples, Temp TC ..................................35
5.4 Continuity Test ..............................................................................36
5.5 Diode Testing with Constant Current of 1 mA ..................................37
5.6 Capacitance Measurement ............................................................38
5.7 Insulation Resistance Measurement – M@UISO ..............................39
5.7.1 Preparing for Measurement ............................................................39
5.7.2 Performing the Insulation Measurement ..........................................40
5.7.3 Ending the Measurement and Discharging ......................................41
5.8 Current Measurement ....................................................................42
5.8.1 Direct and Pulsating Current Measurement, Direct Connection,
A DC and A (DC+AC) ......................................................................43
5.8.2 Alternating Current and Frequency Measurement,
Direct Connection, A AC and Hz ......................................................44
5.8.3 Direct and Pulsating Current Measurement
with Clip-On Current Sensor A DC and A (DC+AC) ...........................45
5.8.4 Alternating Current Measurement with Clip-On Current Sensor,
A AC and Hz ..................................................................................46
5.8.5 Alternating Current Measurement with A AC and Hz Clip-On
Current Transformer .......................................................................47

GMC-I Messtechnik GmbH 7
Table of Contents
Contents Page Contents Page
6 Device and Measuring Parameters ................................... 48
6.1 Paths to the Various Parameters .................................................... 49
6.2 List of All Parameters .................................................................... 49
6.3 Querying Parameters – InFo Menu (as moving letters) ...................... 50
6.4 Entering Parameters – SETUP Menu ............................................... 51
6.5 Default Settings ............................................................................. 53
7 Interface Operation ...........................................................54
7.1 Activating the Interface ................................................................... 54
7.2 Configuring Interface Parameters .................................................... 55
8 Technical Data ................................................................ 56
9 Maintenance and Recalibration ........................................62
9.1 Displays – Error Messages ............................................................ 62
9.2 Batteries ....................................................................................... 62
9.3 Fuses ............................................................................................ 63
9.4 Housing Maintenance .................................................................... 64
9.5 Return and Environmentally Sound Disposal .................................... 64
9.6 Recalibration ................................................................................. 65
9.7 Manufacturer’s Guarantee .............................................................. 65
10 Accessories .......................................................................66
10.1 General ......................................................................................... 66
10.2 Technical Data for Measurement Cables
(scope of delivery: KS17-2 safety cable set) .................................... 66
10.3 Power Pack NA X-TRA (not included) .............................................. 66
10.4 Interface Accessories (not included) ................................................ 67
11 Index .................................................................................68

8GMC-I Messtechnik GmbH
Safety Warnings
1 Safety Features and Precautions
You have selected an instrument which provides you with a high
level of safety.
This instrument fulfills the requirements of applicable European
and national EC directives. This is confirmed by means of the CE
mark. A corresponding declaration of conformity can be
requested from GMC-I Messtechnik GmbH.
The TRMS digital multimeter has been manufactured and tested
in accordance with the following safety regulations:
IEC 61010–1:2001 / DIN EN 61010–1/VDE 0411–1:2002. When
used for its intended purpose (see page 10), safety of the
operator, as well as that of the instrument, is assured. Their safety
is however not guaranteed, if the instrument is used improperly or
handled carelessly.
In order to maintain flawless technical safety conditions, and to assure
safe use, it is imperative that you read the operating instructions
thoroughly and carefully before placing your instrument into service, and
that you follow all instructions contained therein.
The multimeter is equipped with an automatic socket blocking
mechanism for your safety, and in order to safeguard your
instrument. This mechanism is linked to the rotary switch and only
allows access to those jacks which are actually required for the
selected function. It also prevents the user from turning the rotary
switch to impermissible functions after the measurement cables
have already been plugged in.
Measuring Categories and their Significance per IEC 61010-1
The measuring category and the maximum rated voltage which
are printed on the device apply to your measuring instrument, e.g.
600 V CAT III or 1000 V CAT II.
For the application of measuring cables see page 66.
Observe the following safety precautions:
• The multimeter may not be used in potentially explosive
atmospheres.
• The multimeter may only be operated by persons who are
capable of recognizing contact hazards and taking the
appropriate safety precautions. Contact hazards according to
the standards exist anywhere, where voltages of greater than
33 V RMS or 70 V DC may occur. Avoid working alone when
taking measurements which involve contact hazards. Be
certain that a second person is present.
•Maximum allowable voltage between the voltage measuring
sockets or all connector sockets and ground is 1000 V for
measuring category II, and 600 V for measuring category III.
• Be prepared for the occurrence of unexpected voltages at
devices under test (e.g. defective devices). For example,
capacitors may be dangerously charged.
CAT Definition
IMeasurements in electrical circuits which are not directly connected to the
mains: e.g. electrical systems in motor vehicles and aircraft, batteries etc.
II
Measurements in electrical circuits which are electrically connected to the
low-voltage mains: via plug, e.g. in household, office and laboratory applications
III
Measurements in building installations: stationary consumers, distributor
terminals, devices connected permanently to the distributor

GMC-I Messtechnik GmbH 9
Safety Warnings
• Make certain that the measurement cables are in flawless
condition, e.g. no damage to insulation, no interruptions in
cables or plugs etc.
• No measurements may be made with this instrument in
electrical circuits with corona discharge (high-voltage).
• Special care is required when measurements are made in HF
electrical circuits. Dangerous pulsating voltages may be pres-
ent.
• Measurements under moist ambient conditions are not
permitted.
• Be absolutely certain that the measuring ranges are not
overloaded beyond their allowable capacities. Limit values are
included in chapter 8; “Technical Data” in the table entitled
“Measuring Functions and Measuring Ranges” in the
“Overload Capacity” column.
• The multimeter may only be operated with installed batteries or
rechargeable batteries. Dangerous currents and voltages are
otherwise not indicated, and the instrument may be damaged.
• The instrument may not be operated if the fuse cover or the
battery compartment lid has been removed, or if its housing is
open.
• The input for the current measuring range is equipped with a
fuse link.
Maximum permissible voltage for the measuring circuit (= rated
voltage of the fuse) is 1000 V AC/DC.
Use specified fuses only (see page 61)! The fuse must have a
breaking capacity of at least 30 kA.
Repair and Parts Replacement
When the instrument is opened, voltage conducting parts may be
exposed. The instrument must be disconnected from the
measuring circuit before the performance of repairs or the
replacement of parts. If repair of a live open instrument is
required, it may only be carried out by trained personnel who are
familiar with the dangers involved.
Defects and Extraordinary Strains
If it may be assumed that the instrument can no longer be
operated safely, it must be removed from service and secured
against unintentional use.
Safe operation can no longer be relied upon:
• If the device demonstrates visible damage,
• If the instrument no longer functions, or if malfunctioning
occurs,
• After long periods of storage under unfavorable conditions,
e.g. humidity, dust or extreme temperature (see “Ambient Con-
ditions” on page 59).

10 GMC-I Messtechnik GmbH
Safety Warnings
1.1 Use for Intended Purpose
• The respective multimeter is a portable device which can be
held in the hand during the performance of measurements.
• Only those types of measurements described in chapter 5 may
be performed with the measuring instrument.
• The measuring instrument, including measurement cables and
plug-on test probes, may only be utilized within the specified
measuring category (see page 61 and the table on page 8
regarding significance).
• Overload limits may not be exceeded. See technical data on
page 56 for overload values and overload limits.
• Measurements may only be performed under the specified
ambient conditions. See page 59 regarding operating
temperature range and relative humidity.
• The measuring instrument may only be used in accordance
with the specified degree of protection (IP code) (see page 61).
1.2 Meanings of Danger Symbols
Warning concerning a point of danger
(attention: observe documentation!)
Warning concerning dangerous voltage at the measurement
input: U > 15 V AC or U > 25 V DC
1.3 Meanings of Acoustic Warning Signals
Voltage warning: > 1000 V (intermittent acoustic signal)
Current warning: > 11 A (continuous acoustic signal)
!

GMC-I Messtechnik GmbH 11
Safety Warnings

12 GMC-I Messtechnik GmbH
Operating Overview – Connections, Keys, Rotary Switch, Symbols
2 Operating Overview – Connections, Keys, Rotary Switch, Symbols
1 Display (LCD) (see page 13 for significance of symbols)
2 MAN / AUTO shift key for manual/automatic measuring range selection
Increase parameter values
“Operating Mode” menu: Selection of individual menu entries against
the direction of flow
3 ON / OFF | LIGHT key for switching device and display illumination on and off
4FUNC | ENTER multifunction key
“Operating Mode” menu: Acknowledge entry (ENTER)
UISO ON / OFF Insulation resistance measurement
Key for switching insulation resistance measurement on and off
5  Increase measuring range or move decimal point to the right (MAN function)
6 Rotary switch for measuring functions (see page 14 for significance of symbols)
7 DKD calibration mark
8 Connector socket for ground / connected to ground
9 Connector socket for current measurement with automatic blocking
10 Connector socket for voltage, resistance, temperature, diode and
capacitance measurement with automatic blocking
11 DATA / MIN / MAX
Key for freezing, comparing, deleting the measured value, and for Min/Max function
Decrease values
“Operating Mode” menu: Select individual menu entries in flow direction
12 MEASURE | SETUP Key for switching between measuring and menu functions
13 ZERO | ESC
Key for zero balancing
“Operating Mode” menu: Exit menu level and return to a higher level, exit
parameters entry function without saving
14  Decrease measuring range or move decimal point to the left (MAN function)
15 Power pack connector jack
16 Infrared interface
Chap. 3 
Chap. 6
1
3
4
16
5
6
9
Chap. 4.3
Chap. 3
Chap. 5
Chap. 7
Chap. 6

Chap. 3 ff.
Chap. 3
13
12
Chap. 4.1
10
2
Chap. 4.1.2
14
8
Max. 1000 V!
11
15
Chap. 4.1 
Chap. 4.4 
Chap. 6 
Chap. 3.1 
7
Chap. 1.2

GMC-I Messtechnik GmbH 13
Operating Overview – Connections, Keys, Rotary Switch, Symbols
Symbols used in the Digital Display
1 Battery level indicator
2 ON: continuous operation (automatic shutdown deactivated)
3 MAN: manual measuring range selection active
4 Digital display with decimal point and polarity display
5 max/min: Min/Max value storage
6 DATA: display memory, “freeze measured value”
7 STORE: memory mode active
8 ISO: insulation resistance measurement active / selected test voltage
9 1: x current clip factor (transformation ratio)
10 IR: infrared interface display
11 Scale for analog display
12 Pointer for analog display (bar graph – pointer)
triangle appears: indicates overranging
13 Diode measurement selected
14 Selected type of current
15 TRMS measurement
16 Pt100(0): selected platinum resistance thermometer with
automatic recognition of Pt100/Pt1000
17 Type K: temperature measurement with type K (NiCr-Ni) thermocouple
18 sec (seconds): unit of time
19 REL: relative measurement with reference to offset
20 Unit of measure
21 ZERO: zero balancing active
22 Keying Ratio Measurement
(this function only available with customer-specific variant)
23 Warning regarding dangerous voltage: U > 15 V AC or U > 25 V DC
24 Continuity test with acoustic signal active
25 h (hours): unit of time
Battery full
Battery OK
Battery weak
Battery (almost) dead, U < 1.8 V
Data transmission  to /  from the multimeter is active
IR interface in standby mode
(ready to receive starting commands)
Battery level indicator
Interface indicator
12910
12
13
14
15
16
20
23
24
765
1921
8
3
11
18
25
4
22
17

14 GMC-I Messtechnik GmbH
Operating Overview – Connections, Keys, Rotary Switch, Symbols
Symbols used for Rotary Switch positions
Switch FUNC Display Measuring Function Additional Function clip-on (by menu SET  CLIP 1:1/10/100/1000)
V1M0/2 V DC AC TRMS Pulsating voltage, TRMS DC + AC, 15 Hz ... 500 Hz
only for detection of interference voltage!
M 
ISO
@UISO 1UISO/kMInsulation resistance measurement
V~ 0/5 V~ AC TRMS Alternating voltage, AC TRMS, full bandwidth Clip-on AC (V): clip-on current sensor
Hz (V) 1 Hz ~ AC Voltage frequency, full bandwidth Clip-on Hz (V): clip-on current sensor
%2%
Keying Ratio Measurement (customer-specific variant)
V~ 3 V Fil ~ AC TRMS Voltage frequency, with low pass filter (1 kHz)
Hz (V) 4 Hz Fil ~ AC Voltage frequency, with low pass filter (1 kHz)
V 0/2 V DC Direct voltage Clip-on DC (V): clip-on current sensor
V1 V DC AC TRMS Pulsating voltage, TRMS ( ) Clip-on DC + AC (V): clip-on current sensor
0(DC) resistance
0/2 Continuity test with acoustic signal
1V DC Diode voltage where I is constant
Tem p RTD 0C Pt 100/1000
Temperature with Pt 100 / Pt 1000 resistance thermometer
Tem p TC 1C Typ-K Temperature with thermoelement type K
0nF,F Capacitance
A0/2 A DC Direct current value
A1 A DC AC TRMS Pulsating current amperage, AC DC TRMS
A~ 0/2 A~ AC TRMS Alternating current amperage, AC TRMS Clip-on AC (A): clip-on current transformer
Hz (A) 1 Hz ~ AC Current frequency Clip-on Hz (A): clip-on current transformer
1kHz
1kHz
ACDC VAC
2VDC
+=

GMC-I Messtechnik GmbH 15
Operating Overview – Connections, Keys, Rotary Switch, Symbols
User Interface Symbols in the Following Chapters
... Scroll through main menu
... Scroll through submenu
Select decimal point
 Increase/decrease value
time Submenu/parameter (7-segment font)
1nFo Main menu (7-segment font, boldface)
Symbols on the Device
Warning concerning a point of danger
(attention: observe documentation!)
Ground
CAT II / III Measuring category II or III device, see also
“Measuring Categories and their Significance per IEC
61010-1” on page 8.
Continuous, doubled or reinforced insulation
Indicates EC conformity
s IR t Position of the infrared interface, window on the top of the
instrument
Position of the power pack adapter socket,
see also chapter 3.1.
Fuse for current measuring ranges (see chapter 9.3)
The device may not be disposed of with the trash.
Further information regarding the WEEE mark can be
accessed on the Internet at
www.gossenmetrawatt.com under the search term
WEEE (see also chapter 9.5).
Calibration seal (red seal):
See also “Recalibration” on page 65.
!
5 V / 600 mA
Consecutive number
Registration number
Date of calibration (year – month)
German Calibration Service – Calibration Laboratory
B0730
01-04
DKD-K-
19701

16 GMC-I Messtechnik GmbH
Initial Start-Up – Setup
3 Initial Start-Up
3.1 Batteries
Be certain to refer to chapter 9.2 regarding correct battery
installation!
Momentary battery voltage can be queried in the “Info” menu (see
chapter 6.3).
Attention!
!
Disconnect the instrument from the measuring circuit before open-
ing the battery compartment lid in order to replace the batteries.
Operation with Power Pack (not included, see chapter 10.3)
Installed batteries are disconnected electronically if the NA X-TRA
power pack is used, and need not be removed from the
instrument. If rechargeable batteries are used, they must be
recharged externally.
If the external power supply is switched off, the device is switched
to battery operation without interruption.
3.2 Activation
Switching the Instrument On Manually
ÐPress the ON / OFF | LIGHT key until the display appears.
Power-up is acknowledged with a brief acoustic signal. As
long as the key is held depressed, all of the segments at the
liquid crystal display (LCD) are illuminated.
The LCD is depicted on page 13.
The instrument is ready for use as soon as the key is released.
Display Illumination
After the instrument has been switched on, background illumina-
tion can be activated by briefly pressing the ON / OFF | LIGHT key. Il-
lumination is switched back off by once again pressing the same
key, or automatically after approximately 1 minute.
Switching the Instrument On with a PC
The multimeter is switched on after transmission of a data block
from the PC, assuming the “irStb” parameter has been set to “ir
on” (see chapter 6.4).
However, we recommend using the power saving mode: “iroff”.
Note
Electrical discharge and high frequency interference may
cause incorrect displays to appear, and may disable the
measuring sequence.
Disconnect the device from the measuring circuit. Switch the
instrument off and back on again in order to reset. If the
problem persists, briefly dislodge the battery from the
connector contacts (see also chapter 9.2).
3.3 Setting the Operating Parameters
Setting Time and Date
See “tiME” and “dAtE” parameters in chapter 6.4.
Display Modes for the Digital Display
Selection can be made from two different display modes
(see “0.diSP” parameter in chapter 6.4).

GMC-I Messtechnik GmbH 17
Initial Start-Up – Setup
3.4 Switching the Instrument Off
Switching the Instrument Off Manually
ÐPress the ON / OFF | LIGHT key until 0FF appears at the display.
Shutdown is acknowledged with a brief acoustic signal.
Automatic Shutdown
The instrument is switched off automatically if the measured value
remains unchanged for a long period of time (maximum measured
value fluctuation of approximately 0.8% of the measuring range
per minute or 1C or 1F per minute), and if none of the keys or
the rotary switch have been activated before a selected period of
time in minutes has elapsed (see “APoFF” parameter on page 49).
Shutdown is acknowledged with a brief acoustic signal.
Exceptions include:
Transmission and memory mode operation, continuous operation
and whenever a dangerous voltage is applied to the input
(U > 15 V AC or U > 25 V DC).
Disabling Automatic Shutdown
The instrument can be set to continuous operation.
ÐSimultaneously press the
and keys to this end.
The “Continuous On” function is indicated at by means of the
ON display to the right of the battery symbol.
The “Continuous On (on)” setting can be cancelled by changing the re-
spective parameter or by switching the instrument off manually.
In this case the parameter will be reset to 10 min (see “APoFF” on
page 52).
ON / OFF
LIGHT
FUNC
ENTER
ON / OFF
LIGHT
Auto-Range
88.8.8.8
Illumination On
800.00
ON / OFF
LIGHT
Illumination Off
800.00
ON / OFF
LIGHT
0ff
ON / OFF
LIGHT
long
(1 s)

18 GMC-I Messtechnik GmbH
Control Functions
4 Control Functions
4.1 Selecting Measuring Functions and Measuring Ranges
4.1.1 Automatic Range Selection
The multimeter is equipped with auto-ranging for all measuring
functions, except for temperature measurement, and diode and
continuity testing. Auto-ranging is active as soon as the
instrument is switched on. The instrument automatically selects
the measuring range which allows for highest possible resolution
of the applied quantity. When the instrument is switched to
frequency measurement, the previously selected voltage
measuring range remains active.
AUTO-Range Function
The multimeter is switched automatically to the next higher range
at (3099 d + 1 d 0310 d), and to the next lower range at
(280 d - 1 d 2799 d).
With high resolution the multimeter is switched automatically to
the next higher range at (30999 d + 1 d 03100 d), and to the
next lower range at (2800 d - 1 d 27999 d).
4.1.2 Manual Measuring Range Selection
Auto-ranging can be deactivated and measuring ranges can be
selected manually in accordance with the following table by
pressing the MAN / AUTO button.
The desired measuring range can then be selected with the or
key.
The instrument is automatically returned to range selection when
the MAN / AUTO key is pressed, the rotary switch is activated or the
instrument is switched off and back on again.
Overview: Auto-Ranging and Manual Range Selection
* Via manual measuring range selection only
The multimeter is held in the selected measuring range. If the
range limit is exceeded, 0L appears at the display. You should then
switch to the next higher measuring range with the help of the 
key.
Function Display
MAN / AUTO
Manual mode active:
utilized measuring range is fixed MAN
or 
Range switching sequence for:
V: 300 mV*
 3 V  30 V  300 V  1000 V
Hz: 300 Hz
 3 kHz  30 kHz  300 kHz (Hz(U))
:
300  3 k  30 k  300 k  3 M  30 M 
A: 300  A  3 mA  30 mA  300 mA  3  A  10  A
A : See chapter 5.8.3 und chapter 5.8.4
F: 30 nF 300 nF 3F 30F 300F
M 
@ISO
: 300 k  3 M  30 M  300 M  3000 M 
MAN
MAN / AUTO Return to automatic measuring range selection —

GMC-I Messtechnik GmbH 19
Control Functions
4.1.3 Quick Measurements
Measurements performed using a suitable fixed measuring range
are executed more quickly than those which utilize automatic
range selection. Quick measurement is made possible with the
following two functions:
•Manual measuring range selection, i.e. selection of the measuring
range with the best resolution (see chapter 4.1.2)
or
•WiththeDATA function (see chapter 4.4). In this way, the
appropriate measuring range is selected automatically after the
first measurement and the second measurement is executed
more quickly.
The selected measuring range remains active for the subsequent
series of measurements with these two functions.
4.2 Zero Offset / Relative Measurements
Zero balancing or a reference value for relative measurements can
be stored to memory depending upon deviation from the zero
point:
The relevant reference or correction value is deducted individually
for the respective measuring function as an offset from all future
measurements and remains in memory until deleted, or until the
multimeter is switched off.
Zero balancing and reference value adjustment can be used for
auto-ranging, as well as for manual measuring range selection.
Zero Balancing
ÐPlug the measuring cables into the instrument and connect the
free ends to each other, except for capacitance measurement
in which case the ends of the cables are not connected to
each other.
ÐBriefly press the ZERO | ESC key.
The instrument acknowledges zero balancing with an acoustic
signal, and the “ZERO REL” symbol appears at the LCD. The
value measured at the moment the key is pressed serves as a
reference value.
ÐZero balancing can be cleared by once again pressing the
ZERO | ESC key.
Note
As a result of TRMS measurement, the multimeter displays a
residual value of 1 to 10/35 digits with short-circuited
measurement cables as the zero point for V AC / I AC or
V(AC+DC) / I (AC+DC) measurements (non-linearity of the
TRMS converter). This has no influence on specified
accuracy above 1% of the measuring range (or 3% in the
mV, V(AC+DC) ranges).
Setting the Reference Value
ÐPlug the measuring cables into the instrument and measure a
reference value (max. 1500 digits).
Deviation from zero
– with short-circuited measurement cables for V, , A
– with open input for capacitance unit of measure: F
Display
0 to 200 digits ZERO REL
> 200 to 1500 digits REL

20 GMC-I Messtechnik GmbH
Control Functions
ÐBriefly press the ZERO | ESC key.
The instrument acknowledges storage of the reference value
with an acoustic signal, and the “ZERO REL” or the “REL”
symbol appears at the LCD. The value measured at the
moment the key is pressed serves as a reference value.
ÐThe reference value can be cleared by once again pressing the
ZERO | ESC key.
Notes Regarding Relative Measurement
• Relative measurement effects the digital display only. The
analog display continues to read out the original measured value.
• In the case of relative measurement, F or AC quantities may
also appear as negative values.
4.3 Display (LCD)
4.3.1 Digital Display
Measured Value, Unit of Measure, Type of Current, Polarity
The measured value with decimal and plus or minus sign appears
at the digital display. The selected unit of measure and current
type are displayed as well. A minus sign appears to the left of the
value during the measurement of zero-frequency quantities, if the
plus pole of the measured quantity is applied to the “” input.
The “0.diSP” parameter can be used to determine whether lead-
ing zeros will be appear or be suppressed at the measured value
display (see chapter 6.4).
Overranging
If the upper range limit of 3100 digits is exceeded “0L” (overload)
appears at the display.
Exceptions: “0L” appears at the display as of 1000.0 V in the case
of voltage measurement in the 1000 V range, as of 5.100 V for
diode testing, and as of 11.00 A in the 10 A range.
4.3.2 Analog Display
Measured Value, Polarity
The analog display demonstrates the dynamic performance of a
moving-coil mechanism. This display is especially advantageous
for observing measured value fluctuation, and for balancing
procedures.
Display mode Pointer: the current measured value is tracked in
real-time.
The analog scale displays a negative range of 5 scale divisions for
the measurement of zero-frequency quantities, allowing for
precise observation of measured value fluctuation around zero. If
the measured value exceeds the negative range of 5 scale
divisions, polarity is reversed at the analog display.
Scaling of the analog scale is automatic. This is very helpful for
manual measuring range selection.
Overranging
Overranging in the positive range is displayed by means of the
right triangle symbol.
Refresh Rate
In the bar graph and pointer modes, the analog display is
refreshed 40 times per second.