Gossen MetraWatt METRAport 3A User manual

METRAport3A
Analog Multimeter 3-349-303-15
3/6.09
Operating Instructions

2 GMC-I Messtechnik GmbH
1Scale
2 Cover of battery compartment
3 Connection socket „10 A“ for the highest current range
4 Connection socket for the measuring range A|
5 Connection socket for the measuring range V (high potential)
6 Connection socket for all measuring ranges
7 Eye for fastening of the carrying strap
8 OFF|ON: on/off switch (off when the instrument is closed)
9 Potentiometer full scale deflection setting for resistance measurement
10 Function switch and range switch
11 Setscrew for mechanical zero
3
4
5
6
1
2
8
10
73
4
5
6
7
9
11

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Contents
1 Safety Features and Precautions ............................................................4
2 Application ..............................................................................................6
3 Description .............................................................................................6
4 Operation ................................................................................................7
4.1 Controls ...................................................................................................7
4.2 Starting the Instrument ..............................................................................9
4.3 Voltage Measurement .............................................................................10
4.3.1 DC and AC Voltages up to 600 V (Direct Connection) ................................10
4.3.2 DC Voltages up to 30 kV with High Voltage Probe HV 30 ...........................11
4.4 Current Measurement .............................................................................12
4.4.1 DC and AC Currents up to 1 A (Direct Connection) ....................................13
4.4.2 DC and AC Currents up to 10 A (Direct Connection) ..................................14
4.4.3 DC and AC Currents above 10 A with External Shunt .................................14
4.4.4 AC Currents with (Clip-on) Current Transformers ......................................15
4.4.5 DC and AC Currents with (Clip-on) Current Sensors
(Current Transformers with Voltage Output) .............................................16
4.5 Measurement of Composite Voltages and Composite Currents ...................17
4.5.1 Composite Voltages ................................................................................17
4.5.2 Composite Currents ................................................................................17
4.6 Resistance Measurement .......................................................................18
4.7 Test of Diodes and Transistors .................................................................20
5 Technical Data .....................................................................................22
6 Maintenance .........................................................................................26
6.1 Battery ...................................................................................................26
6.2 Melting Fuse ...........................................................................................26
6.3 Housing ..................................................................................................28
7 Repair and Replacement Parts Service
Calibration Center and Rental Instrument Service ...............................28
8 Product Support ....................................................................................28

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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 the applicable European and
national EC guidelines. We confirm this with the CE marking.
The relevant declaration of conformity can be obtained from
GMC-I Messtechnik GmbH.
The analog/digital multimeter has been manufactured and tested in
accordance with safety regulations IEC 61010–1:2001/
DIN EN 61010–1:2001/VDE 0411–1:2002. If used for its intended
purpose, safety of the operator, as well as that of the instrument, is
assured. However, safety cannot be guaranteed if the instrument is
used improperly or handled carelessly.
In order to maintain flawless technical safety condition, 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.
Observe the following safety precautions
• The instrument may only be operated by persons who are capable
of recognizing contact hazards and implementing appropriate
safety precautions. Contact hazards exist anywhere, where volt-
ages of greater than 33 V RMS may occur.
• Avoid working alone when taking measurements which involve
contact hazards. Be certain that a second person is present.
• Maximum allowable voltage between terminals (3), (4), (5), (6) and ground
is equal to 600 V category II or 300 V category III.
• The instrument may only be used for current measurement in power sys-
tems if the electrical circuit is protected with a fuse or a circuit breaker
with a rating of up to 20 A. In order to conform to the CAT requirements,
two fuse links have been fitted for the ranges mA und A.
• Be prepared for the occurrence of unexpected voltages at devices
under test (e.g. defective devices). For example, capacitors may
be dangerously charged.
• Make certain that the measurement cables are in flawless condi-
tion, e.g. no damage to insulation, no interruptions in cables or
plugs etc.

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• No measurements may be performed with this instrument in elec-
trical circuits with corona discharge (high voltage).
• Special care is required when measurements are made in HF elec-
trical circuits. Dangerous pulsating voltages may be present.
• Measurements under moist ambient conditions are not permitted.
• Be absolutely certain that the measuring ranges are not over-
loaded beyond their allowable capacities. Limit values can be
found in the “Measuring Ranges” table in chapter 5 „Technical
Data“.
Meaning of symbols on the instrument
Warning concerning a point of danger
(Attention: observe documentation!)
Earth
Continuous doubled or reinforced insulation
CAT II / III Measurement category II 600 V / III 300 V device
Indicates CE conformity
fuse
This device may not be disposed with the trash. For further details
on the WEEE marking, please refer to our website
www.gossenmetrawatt.com and enter search key ’WEEE’.
!

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Repairs, Parts Replacement and Balancing
When the instrument is opened, voltage conducting parts may be
exposed. The instrument must be disconnected from the measuring
circuit before repair, replacement of parts or balancing. If repair or bal-
ancing of a live, open instrument is required, this 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 uninten-
tional use. Safe operation can no longer be relied upon:
• If the instrument demonstrates visible damage
• If the instrument no longer functions
• After long periods of storage under unfavorable conditions, e.g.
humidity, dust, excessive temperature.
2 Application
The multimeter is an analog multimeter with an electronic amplifier. It
offers a great number of applications in the field of the electrotechnical
practice, e.g. in research and development, manufacture, operation,
test room and service as well as in the field of training and further edu-
cation.
3Description
The multimeter features 46 measuring ranges for DC and AC voltages
up to 1000 V, AC voltage levels from –40 to +62 dB, DC and AC cur-
rents up to 10 A and resistances up to 20 M. It has a constant input
resistance of 10 Mon all voltage measuring ranges.
All measuring ranges are selected with a central range switch. They
are clearly arranged in the turning area of the switch.
Measuring unit and indicating unit are housed in two different case
halves which are connected with each other across a joint with a
stepped stop device. An optimum reading angle can thus be set in all
positions of use for easy reading.

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Several well-tuned protection means protect the instrument against
damage through improper handling and overload within the specified
limit values for overload:
• Overdimensioned precision resistors
• Melting fuse in conjunction with protective power diodes
• Overvoltage arrester
The instrument operates independent of the mains on a commercially
available 9 V flat cell battery. Thanks to the low power consumption of
the electronic components, a long battery life is assured.
The rugged design of the multimeter assures fine protection in the
case of rough mechanical duty. In closed condition, the instrument
offers additional mechanical protection for the measuring unit and the
indicating unit. The connection sockets are protected against acciden-
tal contact. Both the special measuring leads the connection plugs of
which are protected against accidental contact (lead set KS 17) and all
measuring leads with conventional banana plugs (4 mm diameter) can
be used.
4Operation
4.1 Controls
ON/OFF switch
The toggle switch is used to turn the instrument on and off. This switch
should be switched to the "OFF" position when the instrument is not
operated for extended periods of time in order to avoid unnecessary
load on the battery. Apart from that, even a leakproof battery may leak
when the instrument remains turned on for several days with a dis-
charged battery. Damages caused by leaking batteries are not covered
by the instrument warranty.
When the instrument is closed, the battery is automatically discon-
nected.
Range switch
The multimeter has only one rotary switch. All measuring ranges are
selected with it. Without disconnecting the measured variable, it is
possible to switch from the DC voltage ranges to the corresponding
AC voltage ranges or from the DC current ranges to the corresponding
AC current ranges. The measuring circuit is not interrupted when

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changing the current measuring ranges. When making current and
voltage measurements, take care that the range switch is first set to the
highest measuring range. Then work down to lower measuring ranges
until optimum display is obtained.
Attention!
!
When the measuring voltage, e.g. 250 V , is applied, do not
switch to the resistance measuring ranges. From the range
x 100 on there is danger of damaging the contacts of the
range switch.
Eye for fastening of the carrying strap
The carrying strap can be fastened at the eyes. It allows for the instru-
ment to be carried around the neck. Both hands are free for measur-
ing.
Setscrew
for setting of the mechanical zero.
Analog indication
Indication of the measured value is effected by a moving-coil core
magnet movement withspring-loaded jewel bearings on a mirror-
backed scale of a maximum length of 101 mm.
Connection sockets
The instrument has four connection sockets which are protected
against accidental contact. They have the following functions:
Socket „10 A“
connector for the highest current meas. range 10 A .
Socket „A|“ connector for current measuring range up to max.
1 A and for all resistance measuring ranges.
Socket „V“
connector for all voltage meas. ranges (high potential).
Socket „“ common connector for all measuring ranges to
which earth potential of the measured variable has
to be applied. This input is connected with the
shielding within the instrument.

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Special measuring leads the connection plugs of which are protected
against accidental contact (lead set KS 17) as well as all leads with
banana plugs (4 mm diameter) can be plugged onto the sockets.
Melting fuses
for measuring circuit (see also chapter 5).
Potentiometer
for full scale deflection setting when measuring resistance
4.2 Starting the Instrument
Installing the battery
➭ To install or replace the battery, the battery compartment must be opened.
Attention!
!
Remove the measuring leads from the measuring circuit prior
to removing the cover of the battery compartment!
➭Close the instrument.
➭Put a coin or a similar object into the slot between the case and the
cover of the battery compartment and press down.
➭Open the instrument completely and remove the cover of the bat-
tery compartment.
➭Install a 9 V flat cell battery into the battery compartment.
Attention!
!
Only use a leak-proof, 9 V flat cell battery, per IEC 6LR61, if
possible!
➭Reattach the cover of the battery compartment and press onto it
until it engages.
Checking the mechanical zero
Put the multimeter into its position of use, turn off switch and check
the mechanical zero position of the pointer. Correct with the adjust-
ment screw, if required.

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Checking the battery voltage
If the pointer is within the zone marked with the battery symbol „ “
after the instrument has been turned on then the battery voltage is suf-
ficient that is, it is assured that the error limits according to the data
given in chapter 5 „Technical Data“ are maintained.
4.3 Voltage Measurement
Attention!
!
Regardless of the magnitude of the voltage being measured,
for safety reasons, the sum of the voltage being measured
and the voltage to earth must not exceed 600 V CAT II or
300 V CAT III when the multimeter is connected directly!
If possible, take the connection socket, marked „“, immediately to
earth or to the point having the lowest potential to earth when making
any voltage measurements.
4.3.1 DC and AC Voltages up to 600 V (Direct Connection)
➭Set the range switch to posi-
tion 600 V or 600 V~.
➭Connect the measurement
cables as shown.
With DC voltage note the po-
larity! The „“ jack must be
grounded. For safety rea-
sons, leads with connection
plugs that are protected against accidental contact (KS 17) should
be used.
➭Set switch to position „ON“.
➭Work down to lower voltage ranges until optimum indication is ob-
tained.
➭Read the measuring voltage on the VA scale.
Note: Overload protection up to 600 V is provided by a PTC ther-
mistor; cooling time of the thermistor until the start of next measure-
ment:
grant at least 2 minutes.
– / ~+ / ~

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4.3.2 DC Voltages up to 30 kV with High Voltage Probe HV 30
Voltages of greater than 600 V can be measured with a high-voltage
measuring probe, for example the HV3 (up to 3 kV) of the HV30 (up to
30 kV, DC only) from GMC-I Messtechnik GmbH
➭Set the range switch to position 30 V , 100 V or 300 V .
Additional error in indication < 6 % of the full scale value. Furthermore,
class 5 applies to the instrument as it is used as current measuring
instrument with 30, 100 and 300 V for the full scale value (chapter 5,
footnote 1) in the voltage measuring ranges 3, 10 and 30 µA.
Attention!
!
For safety reasons, observe the following when measuring
voltages above 600 V to earth:
Put the multimeter onto an insulated surface and connect the
measuring leads in such a way that the protective lead of the
probe and the „“ socket are directly taken to the protective
conductor (earth) potential. The bonding terminal must be
grounded for this purpose. First, set the range switch to one
of the positions indicated above, and only then turn on the
voltage and scan with the probe respectively.
Do not touch the instrument when the voltage to be measured is
applied!
Measuring Range 3 kV 10 kV 30 kV
Range switch at position 30 V 100 V 300 V
Reading on V, A scale 0 ... 30 0 ... 100 0 ... 30
Multiplication factor x 0,1 x 0,1 x 1
black
black
red
HV30

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4.4 Current Measurement
Attention!
!
The multimeter should be connected into the line having the
lowest voltage to earth. For safety reasons, the voltage to
earth must not exceed 600 V CAT II or 300 V CAT III!
The measuring circuit must be set up mechanically solid and protected
against accidental opening. The conductor cross sections and the
connection points must be designed in such a way that there will be
no unpermissible warm-up. The current measuring ranges
10 µA ... 1 A are protected by a 1.6 A superquick-action melting fuse
(FF 1.6A/600V AC) in conjunction with power diodes. The maximum
breaking capacity of the protective means is 200 A (one half wave)
with a nominal voltage of 600 V and ohmic load.
Attention!
!
Upon cut-out of the protective means, eliminate the cause of
overload before puting the instrument back to serviceable
condition!
The 10 A range is protected by a 16 A superquick-action melting fuse
(FF 16A/600V AC).

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4.4.1 DC and AC Currents up to 1 A (Direct Connection)
➭Disconnect the
power supply to the
measuring circuit
and/or power con-
sumer (RV), and dis-
charge all
capacitors, if avail-
able.
➭Set the range switch
to position
1/10 A or
1/10 A~.
➭Interrupt the mea-
suring circuit and
safely connect the
measuring leads
(without transient resistor!) in series with the power consumer Rv.
With DC current note the polarity!
➭Set switch to position „ON“.
➭Reconnect the power supply to the measuring circuit.
➭Work down to lower current measuring ranges until optimum indica-
tion is obtained. Switching over does not interrupt the measuring
circuit.
➭Read the measured value on the V, A scale.
– / ~+ / ~
RV

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4.4.2 DC and AC Currents up to 10 A (Direct Connection)
➭Disconnect the
power supply to the
measuring circuit
and/or power con-
sumer (RV), and dis-
charge all
capacitors, if avail-
able.
➭Set the range switch
to position
1/10 A or
1/10 A~.
➭Interrupt the mea-
suring circuit and
safely connect the
measuring leads (without transient resistor!) in series with the power
consumer Rv. With DC current note the polarity!
➭Set switch to position „ON“.
➭Reconnect the power supply to the measuring circuit.
➭Read the measured value on the V, A scale 0 ... 100.
4.4.3 DC and AC Currents above 10 A with External Shunt
Measurements of cur-
rents above 10 A are
possible with shunts
(RN), e.g. 100 A/
100 mV.
➭Set the range switch
to position 100 mV,
for instance, de-
pending on the volt-
age drop at the shunt.
➭Then proceed according to chapter 4.4.1.
– (+) / ~+ (–) / ~
RV
– / ~+ / ~
RV
RN

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4.4.4 AC Currents with (Clip-on) Current Transformers
Attention!
!
Prior to closing the primary circuit, verify that the secondary
circult is closed. If current transformers are operated in open
state on the secondary side, e.g. due to defective or not con-
nected leads, due to a blown fuse because of prior overload,
or due to a wrong position of the range switch (not on the cur-
rent range), dangerously high voltages can appear at the con-
nection terminals. Therefore, first check that the current circult
of the measuring instrument and the secondary winding of the
transformer which is connected to the instrument form an
uninterrupted measuring circuit. This can be done for all mea-
suring ranges by means of a resistance measurement as
described in chapter 4.6.
Clip-on current transformers allow for measurements of AC currents
without the need to interrupt the operating circuit. For the use of both
bushing type current transformers and clip-on current transformers the
maximum permissible operating voltage is the rated voltage of the cur-
rent transformer. Take into account the additional error in indication.
V~
M
I(A)

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➭Set the range switch to position A~.
➭Select the measuring range of the multimeter as a function of the
measuring range and the transformation ratio of the clip-on trans-
former.
➭Connect the measurement cables as shown.
➭Set switch to position „ON“.
➭Scan the electrical circuit with the clip-on transformer.
➭Read the measured value by making allowances for the transforma-
tion ratio of the transformer.
➭Disconnect the clip-on transformer from the electrical circuit before
separating the measurement cables from the instrument!
4.4.5 DC and AC Currents with (Clip-on) Current Sensors
(Current Transformers with Voltage Output)
➭Set the range switch to position V or V~.
➭Select the measuring range of the multimeter as a function of the
measuring range and the transformation ratio of the clip-on sensor.
➭Connect the measurement cables as shown.
➭Set switch to position „ON“.
➭Scan the electrical circuit with the clip-on sensor.
➭Read the measured value by making allowances for the transforma-
tion ratio of the transformer.
Example Current Sensor Z13B:
Measuring range of clip-on sensor: 60 A /40 A~,
Output of clip-on sensor: 10 mV/A (max. 600 mV)
Measuring range of multimeter: 1 V /~ 300 mV /~
Indicated value: 150 mV 15.0 A
V/~
I(A)
Load

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4.5 Measurement of Composite Voltages and Composite Currents
The multimeter allows for separate measurements of DC and AC com-
ponents of composite voltages and composite currents.
Attention!
!
The sum of the DC and AC components of the measured vari-
able shall not exceed the permissible limit values for overload
according to chapter 5, and/or the response values of the
protective means!
4.5.1 Composite Voltages
Perform the measurement in accordance with chapter 4.3.
DC voltage measurement with superimposed AC voltage
The AC voltage component may be 5 times the full scale value on
50 Hz and 50 times the full scale value from 500 Hz on. The additional
error is then smaller than 2.5% of the full scale value.
AC voltage measurement with superimposed DC voltage
The sum of the AC voltage and the superimposed DC voltage shall not
exceed the permissible limit values for overload according to
chapter 5.
4.5.2 Composite Currents
Perform the measurements according to chapter 4.4.
On the 10 µA ... 100 mA measuring ranges, the sum of DC and AC
component causes an erroneous indication from the threefold full scale
value on up due to the response of the protective means.

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4.6 Resistance Measurement
For resistance measurement, the
resistance Rxto be measured is
switched in parallel to the internal
resistance. That is why with open
input terminals (Rx= ) the scale
value (full scale deflection) is indi-
cated. The polarity of the voltage to
be measured corresponds to the
markings on the connection sock-
ets „A|“ and „“. The resistance
measuring ranges are protected by
a superquick-action melting fuse
FF 1.6A/600V AC in conjunction
with power diodes. The overload
limit of the protective means is 200 A at a maximum (one half wave)
on 600 Veff.
Attention!
!
Upon cut-out of the protective means:
Check the measuring electric circuit and eliminate the cause
of overload prior to putting the instrument back to serviceable
condition.
On the ranges x1,x 10 and x 100 the open-circuit voltage at
the sockets is approximately 100 mV. The voltage across the device
under test can be read on the 0 ... 100 graduation, whereby 100 scale
parts correspond to 100 mV.
On the ranges kx1andkx 10 the open-circuit voltage at the
sockets is approximately 1 V. The voltage across the device under test
can be read on the 0 ... 100 graduation, whereby 100 scale parts cor-
respond to 1 V. Because the open-circuit voltage is approximately 100
mV on the ranges x1,x 10 and x 100, resistance measure-
ments are possible on circuit boards that are also equtpped with
semi-conductors.
Rx
Voltage Drop

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➭Set the range switch to position x1...kx10.
➭Set switch to position „ON“.
➭With adjustment potentiometer, adjust to full scale deflection .
➭Connect the measurement cables as shown.
➭Read the resistance value on the scale giving consideration to the
multiplication factor.
Attention!
!
Only electrically dead items may be measured. External volt-
ages would falsify the measured result.
After the range switch has been switched from one resistance measur-
ing range to another, always check the full scale deflection and
correct with potentiometer, if required.

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4.7 Test of Diodes and Transistors
The resistance measuring ranges kx 1 and kx 10 are also suited
for coarse functional tests of diodes and transistors. A short circuit or
an interruption of a diode and/or a diode path between base, collector
and emitter of a transistor can be found in a simply way with a "resis-
tance measurement". The polarity of a diode and the base connection
of a transistor can also be found in this way. The device under test
cannot be destroyed as the measuring voltage is 1 V at a maximum
and the measuring current. 2.2 µA or 22 µA at a maximum. From this
limitation of the measuring voltage and the measuring current it fol-
lows, however, that semi-conductors with relatively high reverse and/
or residual current, such as power diodes and power transistors, for
instance, and also rectifiers with several series-connected elements
cannot be tested as, due to the small measuring current, the difference
between the readings in forward and/or reverse direction are not
sufficiently marked.
➭Set the range switch to position kx 1 or kx 10.
➭Set switch to position „ON“.
➭With adjustment potentiometer adjust to full scale deflection.
➭Connect the measuring leads to the sockets „A|“ and „“.
➭Connect diode or transistor according to the following table and
measure both in forward and reverse direction.
➭Read the resistance value on the -scale and the voltage on the V, A
scale with the 100 part graduation.