Rothewald 10002896 User manual

Operating instructions/ Suggested uses
Digital multimeter, Order no. 10002896
Congratulations on purchasing a Rothewald digital multimeter. This is a battery-
powered manual multimeter that can be used for measuring DC and AC
voltages, current strengths and resistances and also for testing diodes.
A protective cover with built-in stand and two test cables are included.
Please follow all the operating and safety instructions to ensure that the unit is
used safely and to keep it in good condition.
Before using this unit with your bike or car, consult your vehicle's repair and
maintenance manual for the requisite measured values and model-specific
measurement instructions.
Improper use of this multimeter may result in damage to the device itself or to
your vehicle!
Control panel
1: 15 mm high LCD display, 3 1/2 digit.
2: Rotary switch for On/Off, and for selecting function and measuring range.
Clockwise rotation selects the following functions / ranges:
Off; AC voltmeter 600 V, 200 V; DC ammeter 20 µA, 200 µA, 2 mA, 20 mA,
200 mA, 10 A; diode testing; ohmmeter 200 Ω, 2 kΩ, 20 kΩ, 200 kΩ, 2 MΩ;
DC voltmeter 200 mV, 2 V, 20 V, 200 V, 600 V.
3: Hold function: if "Hold" is pressed, the display will retain the last measured
value and will indicate this with an "H" symbol until "Hold" is pressed again.
4: 10 A jack, unfused: insert the positive test cable (red) here to measure
currents in the 10 A measuring range.
5: COM jack: insert the negative test cable (black) here.
6: VΩmA jack: insert the positive test cable (red) here to measure voltage,
resistance and DC (up to 200 mA, fused).

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Technical specifications
Display accuracy is guaranteed for a period of one year following calibration at
temperatures between 18 and 28°C and at up to 80% humidity.
Fuse: F 200 mA / 250 V
Battery: 9V battery
Display: 3 1/2 digit, 15 mm high LCD
2-3 updates / sec.
"Measuring range exceeded" message: number "1" appears on the display
"Reversed polarity" message: "-" appears on the display
"Low battery" message: battery symbol appears on the display
Operating temperature: 0 to 40°C
Storage temperature: -10 to 50°C
Max. humidity for storage: 80%, non-condensing
Dimensions: 138 x 69 x 31 mm
Weight: approx. 160 g
Mode Measuring range Resolution Accuracy
DC voltage 200 Mv 0.1 mV +/-(0.5% +/-2 dgts)
2 V 1 mV +/-(0.5% +/-2 dgts)
20 V 10 mV +/-(0.5% +/-2 dgts)
200 V 100 mV +/-(0.5% +/-2 dgts)
600 V 1 V +/-(0.8% +/-2 dgts)
AC voltage 200 V 100 mV +/-(1.2% +/-10 dgts)
600 V 1 V +/-(1.2% +/-10 dgts)
AC voltage frequency 40 to 400 Hz

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DC current 20 µA 0.01 µA +/-(1% +/-2 dgts)
200 µA 0.1 µA +/-(1% +/-2 dgts)
2 mA 1 µA +/-(1% +/-2 dgts)
20 mA 10 µA +/-(1% +/-2 dgts)
200 mA 100 µA +/-(1.5% +/-2 dgts)
10 A 10 mA +/-(3% +/-2 dgts)
10 A for 10 s, 15 mins cool-down period
Resistance 200 Ω 0.1 Ω +/-(0.8% +/-3 dgts)
2 kΩ 1 Ω +/-(0.8% +/-2 dgts)
20 kΩ 10 Ω +/-(0.8% +/-2 dgts)
200 kΩ 100 Ω +/-(0.8% +/-2 dgts)
2M kΩ 1 kΩ +/-(1.0% +/-2 dgts)
Important safety notes
Important safety notes for users:
- This measuring instrument must not be used if damaged. Check that the test
probes, their connections and insulation are all in good condition. Only use the
test cables that were supplied with the unit. Never work in wet or very humid
conditions, if the air contains dust, flammable gases, vapours or solvents, in
thunderstorms, or near powerful electromagnetic fields.
- If the instrument is moved from a cold into a warm environment condensate
may form inside it. It should not therefore be switched on until it has reached
room temperature.
- Always select the measurement function and range carefully. Never exceed
the measuring range. If there is any doubt regarding the measuring range to
be set, then you should start by choosing the widest range possible.
- Always disconnect test cables before switching between the different
measurement functions of voltage, current and resistance. Likewise, always
disconnect the test cables before switching off.
- In the case of voltage measurements there should never be any components
connected to the hFE jack.

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If you switch from one measuring range to another whilst measurement is in
progress, voltage peaks might occur and damage the instrument.
If the voltage exceeds 60 V three-phase or 25 V AC, it is important to take
particular care as there is a risk of electric shock. The test object should
therefore first be de-energised, then the measuring range selected and the
measuring instrument connected to the test object. Only then should voltage be
applied to the test object. Whilst measurement is in progress keep your fingers
behind the shielding on the insulated handle.
Do not use this multimeter for measuring voltage if voltages of above 600 volts
are likely to develop. Do not use this multimeter for measurements in domestic
distribution systems or three-phase networks (380/400 V). Measurements on a
230 V network (e.g. domestic power circuit) are permissible.
- Current strength up to 10 A can be measured. The 10 A range is not fused,
and therefore measurement in this range must only be carried out on circuits
equipped with their own fuses. No voltages of above 250 V are allowed. A
measurement of 10 amps should only continue for 10 s, and must be followed
by a 15 minute cool-down period.
- Never perform resistance measurements on live components.
Maintenance:
If the display is blank, possible causes are:
- the multimeter is not switched on
- the battery is flat ("Battery" indicator may appear on the display)
- the rotary switch may be positioned incorrectly (between two positive
positions)
- If it not possible to measure current, the fuse for the 200 mA range may be
faulty.
Before opening the unit to change the battery or fuse, always unplug the test
cable first and move the rotary switch to "Off". Now, using a suitable Philips
screwdriver, unscrew and remove the Philips screws from the rear side of the
housing and lift off the lower half of the housing.
- Using the wrong fuse can result in fire. You must therefore only ever use a
fuse with the following specification:
F 200 mA / 250 V ("flink")

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- Replace the battery with another one of the same type (9V battery). Be careful
to connect the leads the right way round.
Always close up the housing carefully and tighten all the fastening screws
before starting to use the multimeter again.
Use a damp cloth and a mild cleaning agent to clean the device. Never use
abrasives or solvents
Using the multimeter
A. Measuring a DC voltage:
Important: Never exceed the permissible measuring range of 600 V DC!
Never touch a circuit or components in a circuit if the voltage being
measured is above 25 V AC or 35 V DC!
1. Connect the red test cable to the "VΩmA" jack and connect the black one to
the "COM" jack.
2. Set the rotary switch to the relevant measuring range "V –straight line". If
there is any doubt at first regarding the measuring range, start with greatest
measuring range and then reduce it a little at a time until the ideal measuring
range is found. If any measured value appears on the display although the test
probes have not yet been connected to the object, this can be attributed to the
sensitivity of the measurement input and of no importance.
3. Connect the test probes to the measurement object. If an "-" appears on the
display, this indicates that you have reversed the polarity.
4. Now read the measured value off, retaining it if necessary with the "Hold"
button.
B. Measuring an AC voltage
Important: Never exceed the permissible measuring range of 600 V AC!
Never touch a circuit or components in a circuit if the voltage being
measured exceeds 25 V AC!
1. Connect the red test cable to the "VΩmA" jack and connect the black one to
the "COM" jack.
2. Set the rotary switch to the relevant measuring range "V –wavy line". If at
first there is any doubt about the measuring range, start with the highest

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measuring range and then reduce it as required. If any measured value appears
on the display although the test probes have not yet been connected to the
object, this can be attributed to the sensitivity of the measurement input and of
no importance.
3. Connect the test probes to the measurement object. If an "-" appears on the
display, this indicates that you have reversed the polarity.
4. Now read the measured value off, retaining it if necessary with the "Hold"
button.
C. Measuring a DC current
Important: Do not measure current in circuits in which voltages greater
than 250 V DC can occur!
Do not attempt to measure currents greater than 10 A –the multimeter
would overheat!
Currents of 10 A must only be measured for 10 s, after which the unit
should be disconnected for approx. 15 minutes (cool-down period)!
1. Connect the black test cable to the "COM" jack. For measurements in the mA
range below 200 mA, the red test cable is connected to the "VΩmA" jack, but
for measurements greater than 200 mA, it is connected to the "10 ADC" jack.
2. Move the rotary switch to the desired measuring range "A". If there is any
doubt regarding the measuring range, start with the largest measuring range
and then reduce it (see A. 2.).
3. Connect test probes to the measurement object as shown in the diagram.
4. Read measured value off, retaining it if required with the "Hold" button.
D. Measuring resistance
Important: It is essential that the measurement object should be de-
energized!
To obtain reliable measured values the object's contact points must be
free from dirt, oil, solder lacquer, etc!
1. Connect the black test cable to the "COM" jack and the red test cable to the
"VΩmA" jack. Move the rotary switch to the desired measuring range "Ohms".

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2. Select 200 ohms as the measuring range, hold test probes close together in
order to check the test cable for continuity. The unit should be displaying 0.1 to
0.3 ohms. Now choose the measuring range for the test object (see A. 2.).
3. Hold the test probes near the object and read the measured value off,
retaining it if required with the "Hold" button. If values over 1 ohm are obtained it
may be wise to first wait until the reading has stabilised.
4. If the resistance being measured is connected to a circuit, switch the
instrument off and discharge all capacitors before applying the test probes.
E. Testing diodes
Important: The test object MUST be de-energized, and any connected
capacitors must be discharged!
1. 1. Connect the black test cable to the "COM" jack and the red test cable to
the "VΩmA" jack.
2. Move the rotary switch to the "Arrow Symbol" function.
3. Hold the red test probe against the diode's anode and the black test probe
against its cathode. Now read off the value for the conducting-state voltage
(values between approx. 0.6 V and 3 V depending on diode type). The diode
"blocks" the voltage in one direction –in the "blocked direction" you will obtain
the value "1". If there is again a conducting-state voltage despite reversing the
test probes, this indicates that the diode is faulty.
If you have any questions about these instructions, for prompt assistance
please contact our fax service hotline on [phone] before you
assemble or use the product. This is the best way to ensure that your product is
assembled properly and used correctly.
Detlev Louis Motorradvertriebs GmbH 21027 Hamburg, Germany
http://www.louis.de
Suggested uses for the digital multimeter
Some suggested uses for the digital multimeter with your motorcycle can be
found below.

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When you perform these procedures yourself, be sure to always follow the
safety instructions for using the unit (see user instructions); model-specific
details and target measurement values can be found in the repair and
maintenance manual for your particular vehicle. While we have carefully
researched all the instructions and reviewed them several times, you will
understand that we accept no liability.
1. Check charging circuit
The charging circuit ensures that there is a power supply to the battery and all
consumers (ignition, lights, etc.) on the bike.
- If there are indications that the alternator is not charging the battery sufficiently
(e.g. the headlight is dimming or the battery charging indicator light is flickering),
start with a visual inspection of all the accessible components of the charging
circuit: plug connections should be secure and clean, cables must not show any
sign of damage, wear or fire, the alternator and regulator/rectifier should not
exhibit any obvious signs of mechanical defect.
- To test the individual components further the battery should be in good
condition and fully charged.
- If you identify a fault in part of the charging circuit, also check all the other
components of the circuit for damage.
1.1 Charging voltage
The charging voltage measurement reveals whether or not the charging circuit
is working correctly. First warm the engine up. Now put the bike on its stand and
make the battery terminals accessible. Allow the engine to idle. Insert the red
test cable in the VΩmA jack and the black cable in the COM jack on the
multimeter. Select 20 V DC measuring range. Hold the red test probe against
the positive and the black test probe against the negative battery terminal. Read
off the value –for a well charged 12 V battery the display should now be
indicating approx. 12.6 volts. Now, depending on the model of bike, increase
the engine speed to around 3000-4000 rpm. With a 12 volt system the reading
should now increase to approx. 13.5 to 15.5 volts; in this case the alternator is
charging correctly. If, on the other hand, the voltage stays the same, then there
is a fault in the charging circuit. If the voltage increases beyond the range 13.5

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to 15.5 volts when the engine speed is increased, this indicates that the voltage
regulator/rectifier is not limiting the voltage correctly. Measurable short-term
voltage peaks indicate a fault in the rectifier and/or the alternator.
1.2 Testing a star alternator with a permanent magnet rotor
Star alternators operate with a permanent magnet rotor that induces a voltage
by turning in the windings of the outer stator. They rotate in an oil bath, usually
on the crankpin.
Faults generally occur as a result of persistent overheating or overloading of the
regulator.
Testing non-rectified charging voltage
Stop the engine and switch the ignition off. Disconnect the plug on the cable
harness leading from the alternator to the regulator/rectifier. Insert the red test
cable in the VΩmA jack and the black cable in the COM jack on the multimeter,
select measuring range up to 200 V AC. Use the test probes to connect two of
the alternator's plug contacts. Leave engine running at approx. 3000-4000 rpm.
Measure voltage, stop engine, connect test probes across different contacts,
restart engine, measure voltage again, and so on ... If the measured values are
the same for all the combinations of contacts (as a rule an average motorcycle
alternator delivers approx. 50-70 volts), then the alternator is working correctly.
If some of the measured values are significantly below the others, the alternator
is faulty.
Checking for a short circuit to earth and interturn fault
Stop the engine and switch the ignition off. Insert the red test cable in the
VΩmA jack and the black cable in the COM jack on the multimeter, select
measuring range 200 ohms and hold the test probes close together for the
continuity test until a value of 0.1 to 0.3 ohms is indicated. Now hold the black
test probe against earth and the red one against all the plug contacts one after
the other. There must be no measurable continuity (infinite resistance)
otherwise the stator would have a short circuit to earth. Then use the test
probes to test all possible combinations for connecting the contacts –the
resulting value should always remain slightly less than 1 ohm. If the measured
value is too high, this indicates insufficient continuity between the windings,

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while a measured value of 0 would indicate a short circuit. In both cases the
stator would be faulty.
If the AC voltage at the alternator is considerably too low despite the fact that
the alternator windings are undamaged, it can be assumed that the rotor is
demagnetised.
Testing the regulator/rectifier
If a charging voltage of more than 15 V is measured at the battery when the
engine is running at high revs, either the voltage regulator is faulty (see above)
or it needs to be re-adjusted (some older regulators are adjustable). A rectifier
should be disconnected from its circuit before testing. Insert the red test cable in
the VΩmA jack and the black cable in the COM jack on the multimeter, select
measuring range 200 ohms and hold the test probes close together for the
continuity test until a value of 0.1 to 0.3 ohms is indicated.
Now measure the resistance in both directions between the rectifier's earth
cable and all the alternator connections and also between the positive output
cable and all connections (in other words reverse the polarity once in each
case). One direction should produce a lower reading while the other direction
should produce a reading that is at least 10 times as high. If any of these
connections produces the same value in both directions (i.e. despite reversal of
polarity), this indicates that the alternator is faulty and must be replaced.
1.3 Testing a collector alternator
Collector alternators do not use permanent magnets to induce current; instead
they use the electromagnetic energy from an external field winding. This is
picked up by carbon brushes at the rotor collector. This type of alternator
always runs "dry", either on the crankshaft stump with an external regulator or
as a separate unit, in which case it will usually have an integrated regulator.
Faults are generally caused by vibrations, by shaking due to the rotor's
transverse acceleration, or by asymmetrical thermal stresses. The carbon
brushes and collector are subject to long-term wear.