Gossen MetraWatt METRAmax 2 User manual

Operating instructions
METRAmax 2
Analog Multimeter 3-348-734-02
4/5.06

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Operating Controls
1 Adjustment screw for the mechanical zero
( OFF on scale)
2 Sliding function switch
3 Rotary range selector switch
4 Rotary knob for mid-scale setting of the electrical zero
5 Safety connection sockets
6 Nose to open the meter
7 Battery compartment
9 V
6F22
+
~
1
2
3
4
5
6
7

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Table of Contents
Page
1 Safety Features and Safety Precautions ............................. 4
2 Description ......................................................................... 6
3 Operation ............................................................................ 7
3.1 Initial Start-up ................................................................................... 7
3.1.1 Connecting the Battery ...................................................................... 7
3.1.2 Checking the Mechanical Zero ........................................................... 7
3.1.3 Checking the Electrical Zero .............................................................. 8
3.2 Voltage Measurement ....................................................................... 9
3.2.1 DC Voltage Measurement .................................................................. 9
3.2.2 Direct AC Voltage Measurement up to 300 V ................................... 10
3.2.3 AC Voltage Measurement with Superimposed DC Voltage Component
.10
3.3 Current Measurement ..................................................................... 11
3.3.1 DC Current Measurement ................................................................ 11
3.3.2 DC Current Measurement via Shunts ................................................ 12
3.3.3 AC Current Measurement ................................................................ 13
3.4 End of Measurement ....................................................................... 13
4 Characteristic Values ........................................................ 14
5 Maintenance ..................................................................... 16
5.1 Battery Replacement ....................................................................... 16
5.2 Fuse Replacement .......................................................................... 16
5.3 Cleaning ......................................................................................... 16
5.4 Device Return and Environmentally Compatible Disposal ................... 16
6 Repair and Replacement Parts Service
DKD Calibration Lab
and Rental Instrument Service ......................................... 17
7 Product Support ................................................................ 19

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1 Safety Features and Safety Precautions
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 Gossen-Metrawatt GmbH.
The analog multimeter METRAmax 2 is manufactured in
accordance with safety regulations IEC 61010-1/EN
61010-1/VDE 0411-1. When used for its intended pur-
pose, the safety of the operator, as well as that of the
instrument, is assured. Their safety is however not guaran-
teed if the instrument is used improperly or handled care-
lessly. It is therefore imperative that you read the operating
instructions thoroughly and carefully before placing the
METRAmax 2 into service, and that you follow all instruc-
tions contained therein.
Observe the following safety precautions:
• The instrument may only be operated by persons who
are capable of recognizing contact hazards and taking
the appropriate safety precautions.
• Contact hazards exist anywhere, where voltages of
greater than 30 V may occur (effective value).
• Be prepared for the occurrence of unexpected voltages
at devices under test (e.g. defective devices).
For example, capacitors can be dangerously charged!
• Housing and measurement cables may not be dam-
aged, e.g. by cracks or ruptures.
• No measurements may be made with the METRAmax 2 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 present.

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• Measurements under moist ambient conditions are not
allowable. Hands, shoes, floor and workplace must be
dry.
• Be absolutely certain that the measuring ranges are not
overloaded beyond their allowable capacities.
Meaning of Symbols on the Instrument
indicates EC conformity
Warning concerning a point of danger.
(Attention: observe documentation!)
This 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 by entering the
search term ’WEEE’.
!

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2Description
On the METRAmax 2, the measuring ranges are selected
with a sliding function switch and a rotary range selector
switch. The scale is mirror-backed.
The rugged plastic case and the spring-loaded jewel bear-
ings of the stray-field-insensitive moving-coil movement
with core magnet protect the meter against damages in the
case of severe mechanical stress.
The electrical zero of the pointer can be positioned at mid-
scale. This allows for bipolar DC voltage and DC current
measurements regardless of the polarity.
The connection sockets are protected against accidental
contact. Both the special test leads with contact-protected
connection plugs and all test leads with commercial
banana plugs (4 mm diameter) can be used.
The DC current measuring ranges can be expanded by
means of a shunt (e.g. 10 A/100 mV).
The meter is of service-friendly design.

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3Operation
3.1 Initial Start-up
3.1.1 Connecting the Battery
The battery compartment (7) contains a 9-V battery (IEC
6F22) which is not connected. To connect the battery, it is
required to remove the lower part of the case. For this pur-
pose, press the nose (6) on the front of the meter inwards,
using an adequate tool. Securely connect the battery con-
tacts to the battery clip located in the battery compart-
ment. Ensure reliable contact making. Replace the lower
part of the case and press the two parts together until they
engage.
Attention!
!
Both measurement cables must be disconnected
from the measuring circuit before opening the
meter!
Note
The integrated battery switches off automatically
after 45 minutes. Switching off and on again of the
sliding function switch activates the power supply.
3.1.2 Checking the Mechanical Zero
The METRAmax 2 must not be connected when checking
the mechanical zero.
➭Set the sliding function switch (2) to the "0" position
➭Place the METRAmax 2 in a horizontal position
➭The pointer must be located exactly above the line
marked " OFF"

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➭Correct the deviation by means of the adjustment
screw 1 on the bottom of the case using a screwdriver,
if required.
3.1.3 Checking the Electrical Zero
➭Set the sliding function switch (2) to the position,
select the measuring range
➭The pointer must rest exactly above the line for the zero
at mid-scale
➭Correct deviations by means of the rotary knob (4), if
required
3.1.4 Battery Test
➭Set the sliding function switch (2) to the " " position
➭Set the rotary range selector switch (3) to the " "
position
➭The pointer must travel into the battery test section
marked " "
If the pointer no longer travels into the battery test section,
or if there is an instable indication, the battery is exhausted.
It must be replaced with a new one (see chapter 5.1 on
page 16, Battery Replacement).

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3.2 Voltage Measurement
3.2.1 DC Voltage Measurement
Operating Mode: Electrical Zero at the Left
➭Set the sliding function switch (2) to the position
➭Set the rotary range selector (3) to the corresponding
measuring range position:
V 300 V ... 100 mV
➭Connect the METRAmax 2
➭Read the measured value: black scale
Operating Mode: Electrical Zero at Mid-scale
➭Set the sliding function switch (2) to the position
➭Set the rotary range selector (3) to the corresponding
measuring range position: V 300 V ... 100 mV
➭Check that the pointer rests at mid-scale, see chapter
3.1.3 on page 8
➭Connect the METRAmax 2
➭Read the measured value: red scale +/–
+

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3.2.2 Direct AC Voltage Measurement up to 300 V
➭Set the sliding function switch (2) to the position
➭Set the rotary range selector switch (3) to the corre-
sponding measuring range: V 300 V ... 3 V
➭Connect the METRAmax 2
➭Read the measured value: black scale
To keep the influence of the frequency as low as possible,
the connection socket " " should be connected to the
ground potential as directly as possible or to lowest point
with respect to ground.
3.2.3 AC Voltage Measurement with Superimposed DC Voltage
Component
The DC voltage component, such as occurs with an ampli-
fier output stage, for example, can be cut off by means of a
capacitor (recommended value: 4.7 µF/630 V). In this case,
the additional service error is smaller than 0.2% at a mea-
suring frequency of 50 Hz. The measuring procedure cor-
responds to the one described above.