RAPITEST DM25 User manual

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DIGITAL
MULTIMETER
OPERATOR'S
MANUAL

COTTTETUTS
1. Safety lnformation
1 .1 Preliminary
1.2 During Use
1.3 Symbols
1.4 Maintenance
2. Description
3. Operating lnstruction
3.1 Measuring Voltage
3.2 Measuring Current
3.3 Measuring Resistance
3.4 Testing Diode
PAGE
1
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2
3
4
5
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9
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10
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3.5 Testing Transistor
3.6 Continuity Test
4. Specifications
5. Accessories
5.1 Supplied with the meter
5.2 How to use the holster
6. Battery & Fuse Replacement
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20
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1. SAFETY IIUFORUATIOTI
This multimeter has been designed according to tEC-1010 concerning electronic measuring
instruments with an overvoltage category {CAT ll} and pollution 2.
Follow all safety and operating instructions to ensure that the meter is used safely and is kept
in good operating condition.
1.1 PRELIMII{ARY
r When using the meter, the user must observe all normal safety rules concerning:
- Protection against the dangers of electrical current.
- Protection of the meter against misuse.
o Full compliance with safety standards can be guaranteed only if used with test leads
supplied. lf necessary, they must be replaced with the same model or same electric ratings.
Measuring leads must be in good condition.
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1.2 DURING USE
. Never exceed the protection limit values indicated in specifications for each range of
measurement.
o when the meter is linked to a measurement circuit, do not touch unused terminals'
o when the value scale to be measured is unknown beforehand, set the range selector at the
highest Position-
o Before rotating the range selector to change functions, disconnect test leads from the circuit
under test'
oWhencarryingoutmeasurementsonTVorswitchingpowercircuits,alwaysrememberthat
there may-0" nign amplitude voltages pulses at test points which can damage the meter'
o Never perform resistance measutements on live circuits'
o Always be careful when working with voltages above 6OV dc or 3OV ac rms' Keep fingers
behind the probe barriers while measuring'
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1.3 SYMBOLS
2\tmportant safety information. refer to the operating manual.
.A Dang"rors voltage may be present.
{ rartn ground.
El Doubte insulation (Protection class ll).
. Before attempling to insert transistors for testing, always be sure that leads have been disconnected
from any measurement circuits.
. Components should not be connected to the hFE socket when make in voltage measurements with test leads.
CAT ll: maximum voltage between terminals and earth is 1000V when used on local level, i.e. appliances, portable
equipment, etc
CAT lll: maximum voltage between terminals and earth is 60OV when used on distribution level, i.e, fixed
installations etc -3

1.4 TIIIAINTENANCE
o Before opening the meter, always disconnect test leads from all sources of electric current'
. For continue protection against fire, replace fuse only with the specified voltage and current
ratingsr
F1 F 2AI25OY F2: F 1OA/250V
r lf any faults or abnormalities are observed, the meter can not be used any more and it has
to be checked out.
o Never use the meter unless the back cover is in place and fastened fully'
o To clean the meter, use a damp cloth and mild detergent only, do not use abrasives or
solvents on it.

2. DESCRIPTIOII
This meter is a portable professional measuring instrument with 3% digit LCD' capable of
performing functions:
- DC voltage measurement. 5 ranges from 2OOrnV to 1000V
- AC voltage measurement, 5 ranges from 2OOmV to 70OV
- DC current measurement, 7 ranges trom 2OpA to 1OA
- Ac current measurement, 6 ranges from 200pA to 10A
- Resistance measurement, 7 ranges from 2OOo to 200MO
- Diode test
- Transistor test
- Audible continuity test
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1. Power Switch
2. LCD Display
3. Transistor Testing Socket
4. Rotary Switch
5. V/O lnput Jack
6. COM lnput Jack
7. A lnput Jack
8. 10A Input Jack

2.1 FUNCTION ATTID RAilGE SELECTOR
There are 8 functions and 32 ranges provided. A rotary switch is used to select functions as
well as ranges.
2.2 POWER SWITCH
A push-push switch is used to turn the meter on or off .
To extend the battery life, Auto Power-Off function is provided{Optional). The meter will be
turned off automatically within around 4O minutes. To turn on the meter again, push the power
switch to release it and then push it once more.
2.3INPUT JACKS
This meter has four input iacks that are protected against overload to the limits. During use'
connect the black test lead to the COM jack and the red test lead as shown below:

Function Red Lead Connection lnout Limits
2OOmV
v=/v-
o
n+t
A=I A-
10A
vta
vta
vta
vta
A
10A
250V dc or rms ac
1000V dc or 7O0V rms ac(sine)
25OV dc or rms ac
25OV dc or rms ac
2A dc or rms ac
1OA dc or rms ac
Current ranges are protected by fuses
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3. OPERATI]IIG INSTRUCTION
3.1 MEASURIT{G VOLTAGE
1. Connect the black test lead to the COM jack and the red test lead to the V/O jack'
2. Set the rotary switch at the desired V.=or V - range position and connect test leads across
the source or load under measurement.
3. Read LCD display. The polarity of red connection will be indicated when making a dc
measurement.
4. When only the figure " 1 " is displayed, it indicates overrange situation and the higher range
has to be selected.
3.2 MEASURING CURRENT
1. Connect the black test lead to the COM jack and the red test lead to the A iack for a
maximum of 2A. For a maximum of 1oA, move the red lead to the 10A iack.

2. Set the rotary switch at desired A.-- or A -- range position and connect test leads id series
with the load under measurement.
3. Read LCD display. The polarity of red lead connection will be indicated when making a DC
measurement.
4. When only the figure " 1" displayed, it indicates overrange situation and the higher range has
to be selected.
3.3 MEASURING RESISTANCE
1. Connect the black test lead to the COM iack and the red teas lead to the V/O jack. (NOTE:
The polarity of the red lead connection is positive " + "l
2. Set the rotary switch at desired o range position and connect test leads across the
resistance under measurement. Read LCD display.
NOTE:
1. For resistance above 1MO, the meter may take a few seconds to stabilize reading.
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2. $hen the input is not connected, i.e. at open circuit, the figure "'l " will be displayed for the
overrange condition.
3. When checking in-circuit resistance, be sure the circuit under test has all power removed
and all capacitors are fully discharged.
4. At 2OOMO range display is lOcounts when test leads are shorted. These counts have to be
subtracted from measuring results. For example, when measuring 100M O resistance, the
reading will be 1O1.0 and the correct measuring result should be 1O1.0-1.O=1OO.OMO'
3.4 TESTING DIODE
1. Connect the black test lead to the COM jack and the red test lead to the V/O iack' (NOTE:
The polarity of red lead connection is positive " + "l
2. Set the rotary switch atll-position and connect the red lead to the anode, the black lead to
the cathode of the diode under testing. The meter will show the approx. forward voltage
drop of the diode. lf the lead connection is reversed, only figure "1" will be displayed.
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3.5 TESTING TRANSISTOB
1 . Set the function switch at hFE position'
2. ldentify whether the transistor is NPN or PNP type and locate emitter' base and collector
lead. lnsert leads of the transistor to be tested into proper holes of the testing socket on the
front Panel.
s. lcD iisplay will show the approximate hFE value at the test condition of base current 1OpA
and Vce 3.2V.
3.6 CONTINUITY TEST
1. Connect the black test lead to the COM iack and the red test lead to the V/O jack'
2. Set the rotary switch at t position and connect test leads across two points of the circuit
under testing. lf continuity existsli.e., resistance less than about 7O o l' built-in buzzer will
sound.
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4. SPEC|F|CATIOilS
Accuracy is specified fora period of one year after calibration and at 18oC to 28oC (64oF to
82oFl with relative humidity to 8O%.
4.1 GENERAL
Max. Voltage Between Terminals and Earth
Ground
Fuse Protection
Power Supply
Display
Measuring Method
Overrange lndication
Polarity lndication
Low Battery lndication
Operating Temperature
1OOOV dc or 70OV rms ac (sinel
A: F 2Al250V 1OA: F 1OA/250V
9V battery, NEDA 1 604 or 6F22
LCD, 1999 counts max., updates 2-3lsec
Dual-slope integration A/D converter
" l "displayedonly
" - " displayedautomatically
" E " displayed
ooC to 4OoC (32oF to 104oF) - 13

Storage Temperature
Dimension
Weight
4.2DC VOLTAGE
-1OoC to 50oC (10oF to 't22oFl
91 x 189 ' 3'1 .5 mm
31 Og (lncluding batterY)
Range Resolution Accuracy
2OOmV 0.1mV + O.5olo of rdo + 1 diOits
2V 1mV f O.5olo of rdg t 1 digits
20v 1OmV + 0.5olo of rdq t 1 digits
200v 0.1v t O.5% of rdq t 1 diqits
1 000v 1V t 0.8% of rdg t 2 digits
lnput lmpedance: lOMO
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4.3 AC VOLTAGE
lnput lmpedance: lOMO
Frequency Range: 40 to 4OOHz
Response: Average, calibrated in rms of sine wave
Range Resolution Accuracy
2OOmV O.1mV L 1 .2o/o of rdq t 3 digits
2V 1mV t 0.806 of rdq t 3 diqits
20v lOmV + 0.806 of rdq + 3 diqits
200v o.1v 1 O.8olo ol rdo + 3 diqits
700v 1V + 1 .2o/o of rdo + 3 diqits
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i
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I 4.4 DC CURRENT
Range Resolution Accuracy Burden Voltaoe
2OaA 0.O1/A + 2.OVo of rdg + 5 diqits 10 mV lpA
2OOpA O.'luA + O.8% of rdg + 1 diqits 1.OmV / sA
2mA 1uA + O-8o/o of rdo + 1 dioits 100mV / mA
2OmA lOzA + O.8olo of rdq + 1 dioits 1'lmV / mA
200mA O.1mA + 'l .5o/o of rdo + 1 dioits 2.0mV / mA
2A 'lmA + 1-5o/o of rdg + 1 diqits o.4v tA
10A lOmA + 2-Oo/o of rdq + 5 dioits 0.03v / A
overload Protection: F 24 fuse tor2oyA to 2A ranges, F 1oA fuse for 1oA range.
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4.5 AC CURRETTIT
Overload Protection: F 2A fuse for 2OpA to 2A ranges, F 1OA fuse for 1OA range.
Frequency Range: 4O to 4OOHz
Response: Average, calibrated in rms of sine wave.
Range Resolution Accuracy Burden Voltaoe
2OOpA O.1zA + 'l .8o/o of rdo t 3 diqits 1.OmV / rrA
2mA 1uA + 1 .Oo/o of rdo t 3 diqits IOOmV / mA
2OmA 10zA + 1.Oo/o of rdo + 3 dioits 11mV / mA
200mA O.1mA + 1.8o/o of rdq t 3 diqits 2.OmV / mA
2A 1mA + 1.8o/o of rdq t 3'diqits o.4v / A
10A lOmA t 3.Oolo of rdq + 7 diqits 0.03v / A
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