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

GMC-I Messtechnik GmbH 3
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

4 GMC-I Messtechnik GmbH
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.

GMC-I Messtechnik GmbH 5
• 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’.
!

6 GMC-I Messtechnik GmbH
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.

GMC-I Messtechnik GmbH 7
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

8 GMC-I Messtechnik GmbH
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.

GMC-I Messtechnik GmbH 9
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.

10 GMC-I Messtechnik GmbH
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.
– / ~+ / ~