Gossen MetraWatt METRA HIT 1A User manual

Operating Instructions
METRA HIT 1A/2A
Analog Multimeter 3-349-305-15
5/8.11

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1 Common connection for all measuring ranges (instrument earth)
2 METRA HIT 2A: connection for highest current measuring range 15 A
3 Connection for resistance measurement and capacitance measurement
(negative potential)
4 Connection for all voltage and current ranges
except for METRA HIT 2A: here current measuring range up to 1.5 A
5 Catch for locking the bottom part of the instrument
6 Set screw for mechanical zero setting of the pointer
7 Potentiometer knob
8 Range switch
6
5
34
1
8
7
2

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Contents Page
1 Safety Features and Precautions ......................................4
2 Application ........................................................................6
3 Description ........................................................................7
4 Operation ..........................................................................8
4.1 Controls .........................................................................................8
4.2 Starting the Instrument (ΩMeasurement only) .................................9
4.3 Voltage Measurement ...................................................................10
4.3.1 DC and AC Voltages up to 500 V ...................................................11
4.4 Current Measurement ...................................................................12
4.4.1 DC and AC Voltages (METRA HIT 2A: up to 1.5 A) ...........................12
4.4.2 METRA HIT 2A: Direct and Alternating Currents up to 15 A ..............13
4.5 Resistance Measurements ............................................................14
4.6 Estimated Capacitance Measurement ............................................16
4.7 Measurement of Gain and Attenuation ...........................................17
4.8 Testing Diodes and Transistors ......................................................18
5 Technical Characteristics ...............................................19
6 Maintenace .....................................................................25
6.1 Battery .........................................................................................25
6.2 Housing .......................................................................................25
6.3 Fuses ...........................................................................................25
6.4 Device Return and Environmentally Compatible Disposal .................27
7 Standard Equipment .......................................................28
8 Recalibration ...................................................................29
9 Repair and Replacement Parts Service
DKD Calibration Center
and Rental Instrument Service .......................................30
10 Product Support ..............................................................31

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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 Euro-
pean 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 thor-
oughly 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 any-
where, where voltages 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 (1), (2), (3), (3) and
ground is equal to 500 V category II.

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• The instrument may only be used for current measurement in
power systems 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
condition, e.g. no damage to insulation, no interruptions in
cables or plugs etc.
• No measurements may be performed 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
present.
• Measurements under moist ambient conditions are not per-
mitted.
• Be absolutely certain that the measuring ranges are not
overloaded beyond their allowable capacities. Limit values
can be found in the “Measuring Ranges” table in chapter 4
„Operation“.

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Meaning of symbols on the instrument
Warning concerning a point of danger
(Attention: observe documentation)
Continuous, doubled or reinforced insulation
CAT II Measuring category II instrument 500 V
Ground
Fuse
Indicates EU conformity
2 Application
The multimeter is suited for voltage, current and resistance mea-
surements and for the rough measurement of capacitance. It is
designed for universal use in electronics, radio and television
technology and digital technology and can be used for many
measuring tasks in the field of general electrical technology. The
meter is mainly used in the DIY sector as well as in the fields of
service, eductation and vocational training.
!

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3 Description
The multimeter has measuring ranges for direct and alternating
voltage, direct and alternating current and resistance. Capaci-
tance values can be ascertained by rough measurements.
All the measuring ranges are selected by means of the central
range switch. They are clearly arranged in the rotary section of
the switch.
A mirror is placed behind the scale for accurate reading of the
measured values. The pivots of the measuring element and the
measuring range switch are located in line one above the other,
so that it is also possible to provide long scales for the Ωand dB
measurements. The rugged plastic case and the core-magnet
moving-coil measuring element with its spring-backed jewel
bearings protect the meter against damage when subjected to
rough mechanical stress.
The connection sockets are protected against accidental con-
tact. Both the special instrument leads with shock protection (KS
17) and all measuring leads with conventional banana plugs
(4 mm diameter) can be plugged in.

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4Operation
4.1 Controls
Measuring range switch
The multimeter has only one rotary switch by which all the mea-
suring ranges are selected. The meter can be switched from the
direct voltage ranges to the corresponding alternating voltage
ranges, or from the direct current ranges to the corresponding
alternating current ranges, without switching off the measured
value.
It must be ensured that the measuring range switch is first set to
the highest measuring range when measuring voltage and current.
The switch then has to be switched to lower ranges until the
optimum deflection is obtained.
Connection sockets
The meter has connection sockets with shock-proof protection.
Their functions are as follows:
Socket „⊥“= common connection for all measuring ranges
(instrument earth)
Socket „+15 A = METRA HIT 2A: connection for highest
current measuring range 15 A
Socket „Ω“= connection for resistance measurement and
capacitance measurement (negative poten-
tial)
Socket „+V,A “ = connection for all voltage and current ranges
except for METRA HIT 2A: here up to 1.5 A
The sockets can accommodate the instrument leads with shock-pro-
tected connection plugs as well as all measuring cables with banana
plugs (diameter 4 mm).

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Potentiometer knob
The rotary knob is used to set the full deflection 0 Ωwhen mea-
suring resistance as described in chapter 4.5 and capacitance
according to chapter 4.6.
4.2 Starting the Instrument (ΩMeasurement only)
Inserting the battery
The bottom half must be removed from the instrument in order to
install or exchange the battery.
Attention!
!
Before opening the instrument, the measuring leads
must be disconnected from the measuring circuit!
➭Press the catch on the rear of the instrument, using a test
point, banana plug or similar object, in the direction of the
arrow and remove the lower section.
➭Insert the 1.5 V mignon cell in accordance with the symbol
and pole sign.
Attention!
!
Only use a leak-proof 1.5 V mignon cell according to
IEC LR6/R 6! (AA-Size)
➭Place the instrument in the lower section of the housing and
gently press the two halves together until they lock into
place.
Mechanical zero point check
• Place the multimeter flat on the edge of a table. The lower
third of the instrument should project over the edge.
• Check the mechanical zero setting of the pointer.

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• If necessary, adjust the set screw on the rear of the instru-
ment with a screwdriver to correct the setting.
Battery check
➭Set the range switch to the „Ωx1“position.
➭Short-circuit connecting sockets „⊥“ and „Ω“ using a mea-
suring lead.
➭Set the pointer to full deflection position 0 Ωusing potenti-
ometer knob.
If it is no longer possible to set the full deflection or if the reading
does not remain constant after setting, the mignon cell is spent
or the pigtail fuse is defective.
4.3 Voltage Measurement
Attention!
!
Regardless of the value of the measured voltage, as a
safety precaution, do not exceed the sum of 500 V
CAT II for measured voltage plus voltage against earth
when directly connecting up the multimeter!
The left-hand connection socket marked „⊥“ should be con-
nected whenever possible and for all voltage measurements to
the point with the lowest potential against earth.

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4.3.1 DC and AC Voltages up to 500 V
➭Set range switch to the posi-
tion 500 V or 500 V .
➭Plug test leads into the instru-
ment; (black) test lead to
socket „⊥“ and (red) lead to
socket „+ V, “.
For safety reasons, the test
leads with shock-protected
connection plugs should be
used.
➭Apply the voltage measured to
the test leads. For DC voltage,
socket „⊥“ must be connected
to the negative pole of the
measured voltage and socket
„+ V,A “ to its positive pole.
➭If the measured voltage is less than 150 V, set range switch,
in the case of DC voltage, to the lower DC voltage ranges
and, in the case of AC voltage, to the lower AC voltage
ranges, proceeding until optimum deflection is obtained.
➭Read off the measured value: for DC voltage, on scales
0 ... 5 or 0 ... 15 V, A , for AC voltage, on scales 0 ... 5 or
0 ... 15 V, A .

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4.4 Current Measurement
Attention!
!
The multimeter must always be connected into the lead
the voltage of which is the lowest relative to earth. For
safety reasons, the voltage relative to earth must not ex-
ceed 500 V CAT II! Observe the overload limits, see tables
on page 23.
4.4.1 DC and AC Voltages (METRA HIT 2A: up to 1.5 A)
➭Set range switch to the position
5 A or 5 A (METRA HIT
2A: 1.5 A or 1.5 A ).
➭Plug test leads into the instru-
ment; (black) test lead to socket
„⊥“ and (red) lead to „+ V, A “.
➭Disconnect the power supply to
the measuring circuit, and/or
the power consumer (Rv) and
discharge all capacitors, if avail-
able.
➭Interrupt the measuring circuit
and safely connect the measur-
ing leads (without contact resis-
tance!) in series with the power consumer Rv. Note polarity
sign when measuring direct current! Negative to „⊥“ socket
and positive to „+V, A “ socket.
➭Connect power supply to measuring circuit again.

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➭If the measuring current is less than 500 mA. set the mea-
suring range switch to lower direct current ranges in the
case of direct current, and to lower alternating current
ranges in the case of alternating current, until the optimum
deflection is obtained.
➭Read off the measured value: METRA HIT 1A: for DC on
scale 0 ... 15 V,A , for AC on scale 0 ... 15 V,A .
METRA HIT 2A: for DC on scale 0 ... 15 V,A , for AC on
scale 0 ... 15 V,A .
4.4.2 METRA HIT 2A: Direct and Alternating Currents up to 15 A
➭Set the range switch to the posi-
tion 15 A or 15 A .
➭Plug the test leads into the in-
strument; (black) test lead to
socket „⊥“ and (red) test lead to
socket „+ 15 A “.
➭Disconnect the power supply to
the test circuit or consumer (Rv)
and discharge all capacitors, if
any.
➭Disconnect test circuit and con-
nect test leads safely (no contact
resistance) in series to the con-
sumer Rv. In the case of direct
current, observe the correct pole signs. Negative to socket
„⊥“ and positive to „+ 15 A “.
➭Re-connect the supply to the test circuit.
➭Read off the measured value: for DC on scale 0 ... 15 V,A ,
for AC on scale 0 ... 15 V,A .

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4.5 Resistance Measurements
Resistance is measured with DC
voltage from the 1.5 V mignon cell.
The table of measuring ranges in
chapter 5 gives the maximum mea-
suring currents for full deflection and
a battery voltage of 1.5 V.
Socket polarity is as follows:
Positive pole on socket „⊥“
Negative pole on socket „Ω“
➭Set range switch, depending on
the measured value expected,
to one of the ranges Ωx1...
Ωx1000.
➭Plug in the test leads to sockets
„⊥“ and „Ω“.
➭Short-circuit the test leads.
➭Using the potentiometer knob, set the pointer of the measur-
ing mechanism to full deflection 0 Ω. If it is no longer possi-
ble to set for full deflection or if the reading does not remain
constant after setting, the mignon cell is depleted or the pig-
tail fuse is defective.
➭Connect resistance to be measured Rxto the test leads.

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Attention!
!
Only voltage-free objects may be measured. External
voltages falsify the measuring results and might also
damage the instrument!
➭Read off the value displayed on the Ωscale and multiply by
the factor according to the adjusted measuring range.
If possible, the measuring range should be selected in such a
way as to obtain a reading in the range 5 ... 50 Ω. The measuring
error, in relation to the actual resistance value, is smallest in the
middle of the deflection range. Read off the value displayed on
the Ωscale and multiply by the factor according to the adjusted
measuring range. During resistance measurements of a longer
duration, the full deflection 0 Ωshould always be checked if pos-
sible after moving the range switch from one resistance range to
another and, if necessary, it should be reset.
Note!

Contact resistances at the battery connecting terminals
may, particularly in low ohmic resistance ranges, cause
the setting of full deflection 0 Ωto fluctuate. Conse-
quently, good contact should be ensured, for example
by removing and refitting the battery (see chapter 4.2).

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4.6 Estimated Capacitance Measurement
Capacitance values can be determined in the resistance ranges
by estimated measurement. When doing so, proceed exactly as
if measuring resistance in accordance with chapter 4.5. Resis-
tance Rxis to be replaced by the capacitance to be measured,
after prior discharge. When the capacitor is connected, the
pointer of the instrument swings to a maximum value and then
returns to its initial position (mechanical zero point). The point of
return of the pointer deflection serves as a measure for capaci-
tance. It is to be determined on scale 0 ... 5 V, A . The mea-
sured value can be determined using the following comparative
scale and the factor for capacitance measurement correspond-
ing to the measuring range selected:
Before measurement is repeated, the capacitor must be
recharged!
Example:
Selected measuring range: Ωx 100
Return point of pointer: 3.3 on the upper scale 0 ... 5 V, A
Capacitance determined
via comparative scale:
50 μF
Multiplied by the factor for
capacitance measurement:
50 μF x 10 = 500 μF
Measuring Range Factor for Capacitance
Measurement Measuring Limits
Ω x 1000
Ωx 100
Ωx 10
Ωx 1
μF x 1
μF x 10
μF x 100
μF x 1000
2 ... 200 μF
20 ... 2 000 μF
200 ... 20000 μF
2000 ... 200000 μF

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4.7 Measurement of Gain and Attenuation
In communications engineering, gain or attenuation is almost
exclusively given as a logarithm of the ratio between a measured
voltage and a given reference voltage in dB. In recurrent net-
works, it is thereby possible to determine the total gain or attenu-
ation in a simple manner by adding or subtracting the individual
values. The reference voltage is 0.775 V (1 mW for 600 Ω);
attenuation at this voltage is 0 dB.
For gain and attenuation measurement, proceed exactly as
described in chapter 4.3.1 for AC voltage measurement; the
measured values, however, are to be read off the dB scale.
The range – 15 ... + 6 dB shown on the scale corresponds to the
AC voltage range 1.5 V. In the case of the higher voltage mea-
suring ranges 5 V , 15 V , 50 V ..., 10 dB, 20 dB, 30 dB ...
are to be added to the value read; see the table in chapter 5
showing the voltage measuring ranges.
If a DC voltage is superposed on the AC voltage to be measured,
this can be cancelled out by using a suitable capacitor, which is
to be series-connected to the measuring input.
The operating voltage of the series-
connected capacitor must be at least
of the same magnitude as the peak
value for the voltage applied. If there is
an additional error of 1% of the measured value, it can be calcu-
lated from the formula opposite.
In mentionned formula, Riis the internal resistance of the mea-
suring instrument in the selected measuring range
Cv
1
0,89 f
Hz
----
Ri
MΩ
------
⋅⋅
------------------------- μF⋅≈

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Example:
For a 1 kHz superposed AC voltage, a series-connected capaci-
tor of Cv= 0.0056 μF = 5.6 nF results for the 50 V measuring
range.
Attention!
!
The capacitor is loaded up to the value of the DC volt-
age component. The load can assume a magnitude that
can be lethal and retain this load for quite some time.
The capacitor must therefore be discharged after mea-
surement!
4.8 Testing Diodes and Transistors
The resistance range Ωx 1000 is suitable for approximate func-
tional testing of diodes and transistors. By using a resistance
measurement (see chapter 4.5) it is simple to determine a
short-circuit or interruption of current in a diode or a diode path
between base, collector and emitter in a transistor. This test also
enables the polarity of a diode and the base connection of a
transistor to be determined.
Note!

The positive pole is at socket „⊥“, the negative pole is at
socket „Ω“.
The DUT is not destroyed during this measurement as the volt-
age does not exceed 1.75 V, and the test current does not
exceed 100 μA.

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5 Technical Characteristics
Voltage Measuring Ranges
1) 0dB 0.775 V in the range of 1.5 V ; 0 dB 1 mW at 600 Ω
Input resistance in relation to voltage for : 20.0 kΩ/V
for : 4.0 kΩ/V
METRA HIT 1A: Current Measuring Ranges
Voltage Output 1)Internal Resistance approx.
0.15 V — 3.15 kΩ—
0.50 V — 10.00 kΩ—
1.50 V –15 ... + 6 dB 31.50 kΩ6.50 kΩ
5.00 V – 5 ... + 16 dB 100.00 kΩ20.00 kΩ
15.00 V + 5 ... + 26 dB 315.00 kΩ65.00 kΩ
50.00 V +15 ... + 36 dB 1.00 MΩ200.00 kΩ
150.00 V +25 ... + 46 dB 3.15 MΩ650.00 kΩ
500.00 V +35 ... + 56 dB 10.00 MΩ2.00 MΩ
Current Voltage Drop approx.
50.00 μA 0.158 V —
0.50 mA 1.15 V 1.00 V
5.00 mA 1.25 V 1.25 V
50.00 mA 1.25 V 1.25 V
500.00 mA 1.85 V 1.85 V
5000.00 mA 1.73 V 1.73 V

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METRA HIT 2A: Current Measuring Ranges
Resistance Measuring Ranges
2) for battery voltage 1.5 V
Capacitance Measuring Ranges
3)
Estimated measurement in the resistance measuring ranges;
determination of measured values via comparative scale, see chapter 4.6.
Current Voltage Drop approx.
50 μA 0.158 V —
1.5 mA 1.16 V 1.21 V
15 mA 1.25 V 1.25 V
150 mA 1.25 V 1.25 V
1.5 A 1.95 V 1.95 V
15 A 0.43 V 0.49 V
Resistance Measuring Limits Value at Mid-Scale
(Ri)
Max. Meas. Current
I
max
2)
approx.
Ωx 1 1Ω ... 1 kΩ18.00 Ω83 mA
Ωx 10 10 Ω... 10 kΩ180.00 Ω8.3 mA
Ωx 100 100 Ω... 100 kΩ1.80 kΩ0.83 mA
Ωx 1000 1kΩ... 1 MΩ18.00 kΩ0.083 mA
Capacitance 3) Measuring Limits
μF x 1000 2000 ... 200000 μF
μF x 100 200 ... 20000 μF
μF x 10 20 ... 2000 μF
μF x 1 2 ... 200 μF