3B SCIENTIFIC PHYSICS Escola 2 1006811 User manual

3B SCIENTIFIC® PHYSICS
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Multimeter Escola 2 1006811
Instruction sheet
11/14 SD/UD
1 Meter display with mirror scale
2 Slotted screw for zero calibra-
tion
3 Adjustment knob for zero cali-
bration
4 Measurement range dial
5 Operating mode switch
6 Safety measurement socket
7 Safety ground socket
1. Safety instructions/using the equipment safely
The Escola 2 multimeter is designed to display
electrical measurements in the ranges and
measurement environments specified in its tech-
nical data.
It conforms to safety regulations for electrical
measurement, control and laboratory equip-
ment, as specified in DIN EN 61010-1, protec-
tion class 2 and to excess voltage category CAT I
for up to 30 V. It is intended for measurements on
experiments and laboratory apparatus. It is not
approved for measurements on low-voltage dis-
tribution equipment, such as sockets, fuses, etc.
CAT I: Signal layer, telecommunications, elec-
tronic equipment with only minor excess voltage
transients
CAT II: Domestic appliances, mains sockets,
portable instruments etc.
CAT III: Supply via buried cabling, built-in swit-
ches, automatic circuit breakers, sockets or
contactors
CAT IV: Equipment and installations supplied,
for example, by overhead mains cables and
therefore subject to greater risk of lightning
strikes. This includes, for example, main swit-
ches at the building mains feed, electricity me-
ters and ripple control receivers.
Safe operation of the multimeter is guaranteed if
it is solely used as specified. Safety cannot be
guaranteed, however, if the multimeter is used
incorrectly or handled without due care and at-
tention. In order to avoid serious injury due to
current or voltage shocks, the following safety
instructions are to be observed at all times:

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• Carefully read the instruction manual before
using the multimeter and obey the instruc-
tions therein.
• The multimeter may only be used by per-
sons who are able to recognise the risks of
contact and take due precautions to avoid
them.
This multimeter is not a toy and must not fall into
the hands of children.
• Do not place it, keep it or use it anywhere
within reach of children.
• When the multimeter is used by teenagers,
trainees etc., a suitable person should su-
pervise to ensure the equipment is used
safely.
• If measurements are made where there are
any risks of coming into contact with electric-
ity, a second person is to be informed.
The assumption needs to be made that unfore-
seen voltages may be present in the vicinity of
objects being measured (e.g. faulty equipment
or capacitors).
• Before using the multimeter, check the
housing and measuring leads for damage
and if there should be any malfunctions or
visible damage, the multimeter is not to be
used. Pay specific attention to the insulation
for the measuring sockets.
• Be particularly careful when measuring volt-
ages in excess of 33 V AC (RMS) or 70 V
DC.
• For voltages which are in excess of 33 V AC
or 70 V DC, only use safety measurement
leads conforming at least to CAT II.
• The authorised measuring range is not to be
exceeded. If measurements are made when
the magnitude of the variable is unknown,
always select a large measuring range be-
fore shifting down to lower ones.
• The multimeter may not be used to make
measurement on circuits which exhibit co-
rona discharge (high voltage).
• Particular care is to be taken when making
measurements on high-frequency circuits
where dangerous voltages may arise due to
superimposition of components.
• Make very sure that the voltage value be-
tween the measured contact and earth or
between the ground socket and the meas-
urement socket does not exceed 600 V.
• In order to check that the multimeter is ready
to use, select the battery test function. Af-
terwards, it is then possible to check that the
voltage source is disconnected and no volt-
age is present.
• The multimeter may only be used in a dry,
dust-free environment with no risk of explo-
sions occurring.
• When measuring current in a circuit, make
sure to switch off the power before connect-
ing the multimeter into the circuit.
• When making measurements, always con-
nect the ground lead first. Disconnect the sig-
nal measurement lead before unplugging the
ground.
• Turn off the multimeter before opening the
casing, disconnect the power to the circuit
and the measuring leads from the multime-
ter.
2. Symbol legend
Hazard, read instruction sheet
V Voltage
A Current
Moving coil galvanometer
Apparatus with electronic amplifier
DC quantities accuracy class 2
AC quantities accuracy class 3
Use in horizontal position
Use in vertical position
DC quantities
AC quantities
Needle position zero centre
“OFF” position
Measuring category as per IEC EN
61010-1
Double insulated casing
CE EU conformity mark
Earth symbol
┴
Ground symbol
Battery symbol

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3. Technical data
Dimensions: 98 x 148 x 49 mm
approx.
Weight: 300 g approx.
Scale length: 80 mm
Pointer deflection 0…90°
Operating alignment: Vertical/horizontal
Power supply: 1x 1.5 V, AA IEC LR6
Connectors: 4-mm safety sockets
Voltage ranges: 0.3, 1, 3, 10, 30 V
AC/DC
Internal resistance: 10 kΩ/V
Current ranges: 1, 10, 100, 1000,
3000 mA AC/DC
Voltage drop when
measuring current: 100 mV approx. AC/DC
Accuracy: DC Class 2
AC Class 3
Electrical
zero-point offset: in all DC ranges
Accuracy with
zero-point offset: Class 5
Frequency range: 20 Hz…50Hz…20 kHz
Signal form: Sine (1% max. discrep-
ancy)
Peak factor: 2
Overload protection: Up to ± 50 V AC/DC
peak value
Ambient temperature: 5°C...23°C…40°C
Storage temperature: -20…70°C
Relative humidity: < 85% with no conden-
sation
Shock tests: max. 147 m/s²
Electrical safety:
Safety specifications: EN 61010-1
Excess voltage
category: CAT I: 600 V
Contamination level: 2
Protection type: IP20
Electromagnetic compatibility:
Interference emission: EN 55011:2009
Interference resistance: EN 61326-1:2013
4. Description
The Escola 2 is a meter for use by students to
measure to measure voltages and currents
(both DC and AC quantities) in low voltage
ranges.
All measurement ranges are selected by means
of a rotary dial. Two linearised mirror scales,
graded in a 1:3 ratio, guarantee easy readability
of the measured values.
The trimmer for setting the zero point in the
centre allows the zero point to be set precisely
when it drifts electrically.
AC quantities are calibrated for a sinusoidal
waveform. Conversion and linearisation of the
measurement is achieved by half-wave rectifica-
tion (positive half-wave) using an op-amp. This
makes it possible to acquire qualitative readings
of alternating quantities with signal frequencies
up to in excess of 40 kHz.
The use of a robust moving coil galvanometer
and a mechanically resilient casing make it pos-
sible to use the equipment even under highly
challenging conditions.
The excess current protection of the Escola 2
automatically limits the power when overloaded.
After a brief cooling phase, the multimeter auto-
matically switches on again.
5. Operation
• Switch the multimeter on by select the de-
sired operating mode, or .
• To turn off the multimeter, set the mode
switch to the off position .
• To test the battery, disconnect all leads from
the multimeter, set the operating mode
switch to and the measuring range
switch to . In the range, the
needle should deflect all the way to the end.
If this is not the case, the battery must be
replaced immediately.
5.1 Current and voltage measurements
• Conduct all normal current and voltage
measurements with the operating mode
switch in the position . This way, setting
the measurement range with the measure-
ment range dial automatically takes care of
AC/DC switchovers.
• Connect the lower measurement potential to
the left-hand socket. For DC quantities, the
positive polarity should always be connected
to the right-hand socket.

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5.2 Measurements with the zero position of
the needle centred
This mode of measurement only works for the
DC current and DC voltage ranges.
• For measurements requiring the zero posi-
tion of the needle position to be centred, set
the operating mode switch to the position
.
• Before connecting the external quantity to be
measured, use the adjustment knob to accu-
rately centre the zero position on the scale.
5.3 Selecting measuring range
• Initially set the range selection switch to the
largest possible range, then work down to
lower ranges until the optimum deflection of
the needle is reached.
• Once all measurements have been com-
pleted, turn the selector switch back to the
maximum range again.
5.4 Calibrating zero-point
• Turn on the multimeter, set the maximum
voltage range of 30 V and connect the
ground socket to the voltage socket using a
short lead.
• Set up the multimeter in a horizontal position
and correct the zero-point of the dial with the
help of the adjustment knob.
5.5 Switching off
• Always set the measuring mode to after
completion of measurements to avoid un-
necessary use of the battery.
6. Maintenance
6.1 Changing the battery
All measuring leads must be discon-
nected from the multimeter before the
casing is opened.
• From time to time, check the state of the
battery (see 5. Operation).
Remove discharged or corroded batter-
ies from the multimeter.
During prolonged periods of disuse,
also remove the battery from the mul-
timeter.
• Unscrew the back of the casing.
• Replace flat batteries with 1.5-V alkaline
batteries of size AA IEC LR6.
• Place the negative pole of the battery on the
spring.
The polarity is also marked on the board with
plus and minus symbols. Additionally, a me-
chanical clip on the positive side prevents bat-
tery contact when polarity is reversed.
• Close casing again.
Fig. 1 Changing the battery
• Do not dispose of the
battery in regular
household refuse. Fol-
low the local regula-
tions (In Germany:
BattG; EU:
2006/66/EG).
6.2 Cleaning
• For cleaning, use a soft cloth, slightly mois-
tened with alcohol, or a brush.
• In order to remove a potential electrostatic
charge from the meter display window,
which can easily influence measurements,
follow the instructions above.
Dirt or moisture in the measurement sockets can
affect readings.
• Shake out any dirt that may be in the meas-
urement sockets.
• Soak a new swab with isopropyl alcohol and
work around the inside of each measure-
ment socket.

3B Scientific GmbH ▪Rudorffweg 8 ▪21031 Hamburg ▪Germany ▪www.3bscientific.com
Subject to technical amendments
© Copyright 2014 3B Scientific GmbH
7. Disposal
• The packaging should be disposed of at
local recycling points.
• Should you need to
dispose of the equip-
ment itself, never throw
it away in normal do-
mestic waste. Local
regulations for the dis-
posal of electrical
equipment will apply.
• Do not dispose of the battery in regular
household refuse. Follow the local regula-
tions (In Germany: BattG; EU: 2006/66/EG).