Steren MUL-280 User manual

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Before using your new Digital Multimeter, please read this
instruction manual to prevent any damage. Put them away
in a safe place for future references.
1.- INTRODUCTION
This manual includes information about how to operate this
device and specific instructions for maintaining it. This multimeter
is compact, portable and it works with batteries.
Use this device to measure: AC / DC voltage, AC / DC amp
meter, ohm meter, Audible Continuity Test, diode and transistor
tester, and frequency and capacitor meter.
With a 3-3/4 display, 3260 counts, this multimeter is ideal for
accurate measures. It is an auto-range multimeter with analog
measure-bars. The analog – digital conversion system includes
an high-low A/D converter.
2.- SPECIAL INFORMATION
This multimeter has been developed and tested in accord to IEC.
Following the next operating instructions we will sure that the
meter will keep excellent operating conditions.
Do not use the meter or the testing leads if you find damages
on it.
Make sure to turn the circle off, before soldering or
unsoldering it.
Do not measure resistances if the circuit to be measured is
energized.
Do not measure voltage when the testing leads are con-
nected to 10A or 300mA terminals.
Do not measure values above 1000VDC or 750VCA RMS
Be careful when you are measure values above 60VDC or
30VAC RMS
SYMBOLOGY
It indicates that you need the support of the
user’s manual
It indicates high-voltage in the terminals
•
•
•
•
•
•
Before usin
g
y
our new Di
g
ital Multimeter, please read this
i
nstruction manual to prevent an
y
dama
g
e. Put them awa
y
i
n a safe
p
lace for future references
.

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CAUTION
DO not exceed the maximum limits of the meter, in order to
prevent damages to it
RANGES AND CHARACTERISTICS
The milliampere meter and ampere meter are protected with
fuses.
3.- SPECIFICATIONS
This unit is specified for a one year period in 23˚C+-5˚C
temperatures and 70% relative humidity.
DC VOLT METER (Auto Range)
Input impedance: 10Mmore than 100M for the 360mV range
AC VOLT METER (Auto Range)
DC AMPERE METER (Auto range for μA and mA)
Protection against overcharge: 0,3A/250V fuses
Ran
g
e Resolution Accurac
y
DCV / ACV 1000VCD or 750Vrms
kHz 250VCD or rms CA
250VCD or rms CA
A/mA mA/Cx& COM 300mA CD or rms CA
nF/F mA/Cx& COM 0,3A Fuse protector
A A&COM 10A CD or rms CA
Ran
g
e Resolution Accurac
y
326mV 0,1mV ±0,5% ±2 digits
3,26V 1mV
32,6V 10mV
326V 0,1V
1000V 1V ±0,5% ±1 digit
±0,5% ±1 digit
Ran
g
e Resolution Accurac
y
3,26V 1mV
32,6V 10mV
326V 0,1V
750V 1V
±0,8% ±3 digits
Ran
g
e Resolution Accurac
y
326A 0,1A
3260A1A
32,6mA 10A
326mA 0,1mA
10A 10mA ±2,0% ±5 digits
±1,2% ±3 digits

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AC AMPERE METER (Auto range for μA and mA)
Protection against overcharge: 0,3A/250V and 10A/250V fuses
FREQUENCY METER (Auto range)
Sensitivity: 200mV 0—50kHz and 1V 50kHz to 200kHz
CAPACITOR METER (Manual range)
OHMMETER (Auto range)
4.- GENERAL CHARACTERISTICS (DISPLAY)
Analog: 32 segments, 12,5 seconds
Digital: 3260 counts, 2 seconds.
Polarity indicator “-“ automatically
Overcharge indicator : “OL” on screen
Low battery indicator: on screen
Operating temperature: 0° to 40°C, less then 75% of humidity
Battery: 9V
Dimensions (mm): 91 x 189 x 31,5
Weight : 310g approx.
Accessories: user’s manual, battery and testing points.
Ran
g
e Resolution Accurac
y
326A 0,1A
3260A1A
32,6mA 10A
326mA 0,1mA
10A 10mA ±3,0% ±7 digits
±1,5% ±5 digits
Ran
g
e Resolution Accurac
y
32,6kHz 10Hz ±1,2% ±3 digits
200kHz 100Hz ±2,5% ±3 di
g
its
Ran
g
e Resolution Accurac
y
326mA 0,1nF
32,6A 10nF ±3,0% ±5 digits
Ran
g
e Resolution Accurac
y
±0,8% ±3 digits
±1,2% ±2 digits
±0,8% ±1 digit

APPEREANCE AND PART LIST
1.- Range selector
2.- Hold button
3.- DC / AC / selector
4.- Transistor tester
5.- Function dial
6.- “V/F” Jack
7.- “Common” jack
8.- “mA/Cx” jack
9.- “10A” jack
5.1. RANGE SELECTOR
DC / AC voltage range selector, DC/AC current (only for A
and mA), the ohmmeter and frequency meter functions can be
selected manually or using the auto range key. The way to use
this button is:
1
2
9
8
3
4
6
7
5
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5.2. HOLD BUTTON
When this button is pressed, the “D-H” symbol displays in the
screen, and the reading value will be showed until you press the
hold button once again. This function may be cancel
automatically turning the function button.
5.3 DC / AC SELECTOR BUTTON
Press this button to switch between DC or AC, for the volt meter,
ampere meter, diodes and continuity tester.
OPERATING INSTRUCTIONS
6.1 DC / AC VOLT METER
a) Connect the red testing point to the jack signaled “V ” and
the black testing point to the jack signaled “COM”.
b) Set the dial to the VDC / VAC setting, select the range and
begin to measure.
c) The polarity will appear on the LCD screen when you performs
DC measures.
6.2 DC / AC AMPERE METER
a) Connect the red testing point to the jack signaled “mA/Cx”
when measuring up to 300 mA and the red testing point to the
jack signaled “COM”. When measuring up to 10A connect the
red testing point to the jack 10A
Power on / Change of function
Autorange
Manual
Change of range
Press the button for
more than 3 seconds
Press once, “R-H”
will be displayed in
the screen
Pres the button for
less than 1 second
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b) Set the dial to the VDC / VAC setting. Select the A, mA or A
function, and the range.
c) Connect the testing points to the equipment to be measured.
d) Read the polarity in the screen, in AC measures.
6.3 OHMMETER
a) Connect the black testing point to COM and the red testing
point to V/ / F. The polarity of the red testing point is “+”.
b) Set the dial to the setting, the range and begin t measure.
For resistances above 3,6M Ω, the meter will late a couple of
seconds to stabilize the reading. This is normal for
high-resistance readings.
If a circuit is open, the word “OL” displays in the screen, as
in the overload range.
If you’ll test the resistance of a circuit, make sure to
disconnect it and the capacitors are totally discharged.
c) if you test the continuity in a circuit resistance, it must be less
than 20 to obtain an audible signal.
d) To obtain the reading of direct voltage polarization, during
diodes test, connect the red testing point to the anode and the
black testing point to the cathode.
6.5 MEASURING CAPACITY
a) Connect the black testing point to COM and the red testing
point to mA/Cx
b) Set the dial to the “nF” or “F” range. The red testing point will
be positive.
c) Connect the testing points to the equipment to be measured.
Check the polarity.
Before test capacitors, make sure the circuit is not
energized and the capacitors are discharged.
The capacitometer has only two ranges, and the selection of
one of them is manually (326nF and 32,6μF)
If the range button is pressed, the decimal point can be
placed in a wrong position.
6.6. MEASURING FREQUENCY
a) Connect the black testing point to COM and the red testing
point to V/ / F.
F
or resistances above 3,6M Ω, the meter will late a cou
p
le of
s
econds to stabilize the readin
g
. This is normal for
hi
g
h-resistance readin
g
s
.
I
f a circuit is open, the word “OL” displa
y
s in the screen, as
i
n the overload ran
g
e
.
I
f
y
ou’ll test the resistance of a circuit, make sure to
di
sconnect
i
t an
d
t
h
e capac
i
tors are tota
lly
di
sc
h
ar
g
e
d.
Before test ca
p
acitors, make sure the circuit is not
e
ner
g
ized and the capacitors are dischar
g
ed.
T
he capacitometer has onl
y
two ran
g
es, and the selection of
o
ne of them is manuall
y
(
326nF and 32,6μF
)
I
f the ran
g
e button is pressed, the decimal point can be
p
laced in a wron
g
position
.
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b) Set the dial to the right position. Connect the testing points to
the circuit to be measured. Must be between 200mV and 10V
rms of AC, if is higher than those, the accurate of the reading
may be less.
6.7. TRANSISTOR MEASUREMENT
a) Set the dial to the hFE range.
b) Determine if the transistor is NPN or PNP and localize the
emitter, base, and collector. Connect the testing points in the
jacks for transistor testing.
c) The multimeter will show the grade of transistor amplification
with base current condition of lb-10A and VCE 3,2 V
7.- MAINTAINING
7.1 Replacing the battery
When the energy of the battery is low, a small battery icon
displays in the screen. To replace the battery, you must remove
the screws from the back cover.
7.2 Replacing the fuse
Use fuses with next specifications: (0,3A/250V and 10A/ 250V)
WARNING
TO PREVENT ELECTRICAL SHOCK
Before removing the cover from your multimeter, make sure the
testing points are disconnected to avoid the risk of electrical
shock.
Do not operate the meter if it’s not placed in a solid and stable
surface.
The characteristics for this multimeter are subject to change
without notice.
T
he characteristics for this multimeter are sub
j
ect to chan
g
e
w
ithout notice
.
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WARRANTY
This Steren product is warranted under normal usage agains defects in
workmanship and materials to the original purchaser for one year from the date of
purchase.
CONDITIONS
1.- This warranty card with all the required information, invoice or purchase ticket,
product box or package, and product, must be presented when warranty service is
required.
2.- If the product stills on the warranty time, the company will repair it free of charge.
3.- The repairing time will not exceed 30 natural days, from the day the claim was
received.
4.- Steren sell parts, components, consumables and accesories to costumer, as well
as warranty service, at any of the addresses mentioned later.
THIS WARRANTY IS VOID IN THE NEXT CASES:
If the product has been damaged by an accident, acts of God, mishandling, leaky
batteries, failure to follow enclosed instructions, improper repair by unauthorized
personnel, improper safe keeping, among others.
a) The consumer can also claim the warranty service in the purchase establishment.
b) If you lose the warranty card, we can reissue it, if you show the invoice or
purchase ticket.
RETAILER INFORMATION
Name of the retailer
Address
Product
Brand
Part number
Serial number
Date of delivery
In case your product fails, contact a closer retailer. If you have any doubt,
please give a call to our Call Center.
Call Center
Mexico City: 53 54 22 90
Province: 01 800 500 9000