REED ST-3347 User manual

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Model ST-3347
AC/DC True RMS
Clamp Meter
Instruction
Manual

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Table of Contents
Measuring Limits .................................................................................2
Safety Information ........................................................................... 3-5
Features...............................................................................................5
Meter Description................................................................................6
Specications.................................................................................. 6-7
DC Current Measurement ...................................................................8
AC TRMS Current Measurement.........................................................9
DC Voltage Measurement .................................................................10
AC TRMS Voltage Measurement.......................................................11
Resistance Measurement..................................................................12
Capacitance Measurement ...............................................................13
Frequency Measurement...................................................................14
Temperature Measurement ...............................................................15
Diode Test..........................................................................................16
Continuity Testing..............................................................................17
Data Hold Functions..........................................................................18
Peak Hold Functions .........................................................................18
LCD Backlight ...................................................................................18
Auto Power Off..................................................................................19
Battery Replacement.........................................................................19
Measuring Limits
DC Amperes: 0.01A to 1000A AC Amperes: 0.01A to 1000A
DC Voltage: 0.1mV to 600V AC Voltage: 0.1mV to 600V
Resistance: 0.1Ωto40MΩ Capacitance: 0.001 nF to 40mF
Frequency: 0.001 kHz to 4kHz Temperature: -40°C to 1000°C
-40°F to 1832°F

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Safety Information
This manual contains information that must be followed to operate the
meter safely and maintain the meters safe operating condition. If the
meterisnotusedinamannerspeciedinthismanual,theprotection
provided by the meter may be impaired.
The model has been designed and complies With IEC 61010-1 and
EN 61010-1 Safety Requirements for Electronic Measuring Apparatus.
WARNING
• Read through the operating instructions throughly and understand the
instructions before operating the meter.
• Keep the manual at hand so as to enable quick reference when necessary
• Ensure that the use of the meter is in its intended applications and
follow measurement procedures described in this manual.
• Follow all safety and operating instructions to ensure maximum
personal safety during the use and operation of the meter.
• Failuretofollowtheaboveinstructionsmaycauseinjury,instrument
damage and/or damage to the equipment under test.
• The symbols indicated on the meter means that the user must refer to
related parts in the manual for safe operation of the meter. Be sure to
carefully read the instructions following each symbol in this manual.
DANGER is reserved for conditions and actions that are likely
to cause serious or fatal injury.
WARNING is reserved for conditions and actions that are likely
to cause serious or fatal injury.
CAUTION is reserved for conditions and actions that are likely
to cause minor injury.

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Danger
• Never use the meter to measure voltages on a circuit above the maxi-
mum allowable input value on any function.
• Do not exceed the maximum allowable input of any measurement range.
• Nevertouchexposedwiring,connectionsoranylivecircuitwhenat-
tempting to take measurements.
• Donotattempttomakemeasurementsinammablegaseousareas,
fumes,vaporordust.Theuseoftheinstrumentintheseareasmaycause
sparking,whichcanleadtoanexplosion.
• Do not attempt to use the instrument if its surface or your hand is wet.
• Never open the battery compartment cover when making measurements.
Warning
• Always inspect the meter and test leads for any signs of damage or
abnormalities before use. If the meter or its accessories have any
structuraldefectssuchasbrokentestleads,crackedcases,exposed
metalpartsorthedisplayisnotreading,donotattempttomake
measurements.
• Do not turn the function switch while test leads are connected to the meter.
• Donotinstallsubstitutepartsormakemodicationstothemeter.
Return the meter to your distributor for repair or re-calibration. For
serviceonthisoranyotherREEDproduct,contactREEDInstruments
at [e-mail].
• Ensure the meter is switched off before opening the battery cover when
replacing the battery.
• Never replace a battery if the surface of the meter is wet or moist.

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Caution
• Before making measurements ensure that the function selector switch
is set on the appropriate range position.
• Always make sure that the plug of each test lead is inserted fully into
the appropriate terminal of the meter.
• Ensure that the function selector switch is set to the “OFF” position
afteruse.Whenthemeterwillnotbeinuseforalongperiodoftime,
place it in storage after removing the battery.
• Donotexposethemetertodirectsunlight,extremetemperaturesor
moisture.
• Do not use abrasives or solvents on the meter. To clean it use a damp
clothandmilddetergentonly.Onlyqualiedandtrainedservicetechni-
cians should perform calibration and repair of the meter.
ForserviceonthisoranyotherREEDproduct,contactREEDInstruments
at [e-mail].
Features
• True RMS measurement of AC Current and AC Voltage
• Large 4000 count LCD display with a bargraph and a bright white LED backlight.
• Wide measuring range from 0.01A AC/DC up to 1000A AC/DC
• Measures AC and DC Voltage up to 600 volts
• Measuresresistancefrom0.01Ωupto40MΩ.
• Capacitance measurements up to 40mF
• Temperature measurements from -40°C to +1000°C and -40°F to +1832°F
• Designed to the international safety standard IEC61010 CAT III 600V /
CAT II 1000V. Pollution degree 2.
• Auto Power Off after approximately 20 minutes to conserve battery life.
• Continuity Buzzer and Diode Test.
• Frequency measurement up to 4kHz.
• Peak Hold to record the minimum and maximum readings for current & voltage.
• Data Hold switch used to freeze reading on display

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Transformer
Jaws
Function Switch
DC Amps Zero Adjustment
Backlight Button
Display
Volt,Resistance,Frequency,
Capacitance,Temperature,
Terminal
Jaw Trigger
Data Hold Button
Mode Button
Peak Hold Button for
Volts and Current
COM Terminal
Meter Description
Specifications
Clamp Size 30mm Opening Approx
Diode Test Test Current of 0.3mA typical;
Open circuit voltage 1.5V DC
ContinuityCheck Thershold<35Ω;Testcurrent<1mA
Low Battery indication is displayed
Overrange Indication “OL” is displayed
MeasurementsRate 2persecond,nominal
InputImpedance 10MΩ(VDCandVAC)
Display 4000 count LCD
ACCurrent 50/60Hz(AAC)
ACVoltageBandwidth 50/60Hz(VAC)
OperatingTemperature -10°Cto50°C(14°Fto122°F)
StorageTempertaure -30°Cto60°C(-22°Fto140°F)
Relative Humidity Up to 85%
Over Voltage Category III 600V
Battery One DC 9V IEC 6F22. 1604. Battery
Auto Power Off Approx 20 minutes
Dimensions 229 x 80 x 49mm
Weight 303g

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Range Measuring Range Resolution Accuracy (% of Reading)
DC CURRENT
40A 0 ~ 40.00A 0.01A ±(2.8%+10digits)
400A 0 ~ 400.0A 0.1A ±(2.8%+8digits)
1000A 0 ~ 1000A 1A ±(3.0%+8digits)
AC CURRENT
40A 0 ~ 40.00A 0.01A ±(2.8%+10digits)
400A 0 ~ 400.0A 0.1A ±(2.8%+8digits)
1000A 0 ~ 1000A 1A ±(3.0%+8digits)
DC VOLTAGE
400mV 0 ~ 400mV 0.1 mA ±(0.8%+2digits)
4V 0 ~ 4.000V 0.001V
±(1.5%+2digits)
40V 0 ~ 40.00V 0.01V
400V 0 ~ 400.0V 0.1V
600V 0 ~ 600A 1V ±(2.0%+2digits)
AC VOLTAGE
400mV 0 ~ 400mV 0.1 mA ±(1.0%+10digits)
4V 0 ~ 4.000V 0.001V
±(1.5%+8digits)
40V 0 ~ 40.00V 0.01V
400V 0 ~ 400.0V 0.1V
600V 0 ~ 600A 1V ±(2.0%+8digits)
Note: No Autoranging on 400mV AC Range
RESISTANCE
400Ω 0~400.0Ω 0.1Ω ±(1.0%+4digits)
4kΩ 0~4.000kΩ 1Ω
±(1.5%+2digits)
40kΩ 0~40.00kΩ 10Ω
400kΩ 0~400.0kΩ 100Ω
4MΩ 0~4.000MΩ 1kΩ ±(2.5%+5digits)
40MΩ 0~40.00MΩ 10kΩ ±(3.5%+10digits)
CAPACITANCE
4nF 0 ~ 4.000nF 0.001nF ±(5.0%+30digits)
40nF 0 ~ 40.00nF 0.01nF ±(5.0%+20digits)
400nF 0 ~ 400.0nF 0.1nF
±(3.0%+5digits)
4µF 0 ~ 4.000µF 0.001µF
40µF 0 ~ 40.00µF 0.01µF
400µF 0 ~ 400.0µF 0.1µF ±(4.0%+10digits)
4mF 0 ~ 4.000mF 0.001mF ±(4.5%+10digits)
40mF 0 ~ 40.00mF 0.01mF ±(5.0%+10digits)
FREQUENCY
4kHz 0 ~ 4.000kHz 0.001kHz ±(1.5%+2digits)
Sensitivity: 5Vrms min
TEMPERATURE
°C -40°C ~ 1000°C 1°C ±(2.5%+3°C)
°F -40°F ~ 1832°F 1°F ±(2.5%+5°F)

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DC Current Measurement
Warning
Ensure that the test leads are disconnected from the
meter before making current measurements.
1. Set the Function switch to 1000A or 400A or 40A rangeposition,and
make sure that the current under test does not exceed the upper limit
of the measuring range you have selected. The meter automatically
defaults to DC Current.
2. Press the DC ZERObuttononce,the sign will appear on the LCD
indicating Range is zero.
3. Press the trigger to open up the transformer jaws and clamp around
the single conductor under test.
4. Read the display.
Notes:
• Duringcurrentmeasurementskeepthetransformerjawsfullyclosed,
otherwise it will affect the accuracy of the measurement.
• When large currents the transformer jaws may buzz. This is not a fault
and does not affect the accuracy of the reading.
Correct Current Incorrect Current
Measurement Measurement

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AC True RMS Current Measurement
Warning
Ensure that the test leads are disconnected from the meter
before making current measurements.
1. Set the function switch to 1000A~ or 400A~ or 40A~rangeposition,
and make sure that the current under test does not exceed the upper
limit of the measuring range you have selected
2. Press the MODE button to select the AC Current range. The meter
automatically defaults to DC current
3. Press the trigger to open up the transformer jaws and clamp around
the single conductor under test.
4. Read the display.
Notes:
• Duringcurrentmeasurementskeepthetransformerjawsfullyclosed,
otherwise this will affect the accuracy of the measurement.
• When large currents the transformer jaws may buzz. This is not a fault
and does not affect the accuracy of the reading.
• The meter is set to default to “Auto Range” mode.
• Pressing the PEAK hold button will allow the user to record the peak
maximum and minimum readings on the AC volt range. See page 17 for
further Instructions for “PEAK” Hold function
Correct Current Incorrect Current
Measurement Measurement

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DC Voltage Measurement
1. Set the Function switch to range position.
The meter automatically defaults to DC Volts.
2. Insert the red test lead into the “V Ω TEMP HZ” input terminal
and the black lead to the “COM” terminal.
3. Connect the other end of the test leads to the circuit under test.
4. Read the display. If a “-”signisdisplayed,theredlead
is the negative potential.

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AC True RMS Voltage Measurement
1. Set the function switch to range position.
2. Press the MODE button to select the AC Volt range.
The meter automatically defaults to DC Volts.
3. Insert the red test lead into the “V Ω TEMP HZ” input terminal
and the black lead to the “COM” terminal.
4. Connect the other end of the test leads to the circuit under test.
Take the reading on the display.
Notes:
• The meter is set to default to “Auto Range” mode
• Pressing the “PEAK” hold button will allow the user to record the peak
maximum and minimum readings on the AC volt range. See page 17 for
further instructions for “PEAK” Hold function.

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Resistance Measurement
1. Set the function switch to range position. The meter auto-
matically defaults to resistance range.
2. Insert the red test lead into the “V Ω TEMP HZ” input terminal and the
black lead to the “COM” terminal.
3. Connect the other end of the test leads to the circuit or component
under test. Take the reading on the display.
Notes:
• The meter is set to default to “Auto Range” mode
• WARNINGbeforeattemptingtomakearesistancemeasurement,
ensure there is no voltage present on the circuit under test.

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Capacitance Measurement
1. Set the function switch to range position.
2. Insert the red test lead into the “V Ω TEMP HZ” input terminal
and the black lead to the “COM” terminal.
3. Connect the other end of the test leads to the circuit or component
under test. Take the reading on the display.
Notes:
• In Capacitance range the meter is Auto Ranging only.
• CAUTION to avoid damage to the meter or the equipment under
test,removeallpowerfromthecircuitanddischargeallcapacitors
beforemeasuring capacitance.
• Large value capacitors should be discharged through an appropriate
resistanceload.UsetheDCVoltagefunctiontoconrmthatthe
capacitor is discharged.

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Frequency Measurement
1. Set the function switch to range position.
The meter automatically defaults to Frequency range.
2. Press the MODE button for 3 seconds to select the Frequency range.
The meter automatically defaults to DC Volts.
3. Insert the red test lead into the “V Ω TEMP HZ” input terminal and the
black lead to the “COM” terminal.
4. Connect the other end of the test leads to the circuit or component
under test. Take the reading on the display.
Note:
• In the Frequency range the meter is Auto Ranging only.

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Temperature Measurement
1. Set the function switch to TEMP range position.
The meter automatically defaults to °C range.
2. Insert the meter white temperature adaptor into the “V Ω TEMP HZ”
input terminal and the “COM” terminal. Ensure that the “-” marking on
the adaptor is inserted into the “COM” terminal and the “+” marking
on the adaptor is inserted into the “V Ω TEMP HZ” Input terminal.
3. Connect any K-Type probe into the meter adaptor and measure the
temperature of the apparatus or area required.
4. Read the temperature directly on the display.
5. Tochangethemeasuringunitfrom°Cto°F,
Press the MODE button to select the °F unit.
Note:
• The meter is set to default to “Auto Range” mode.

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Diode Test
1. Set the function switch to range position.
2. Press the MODE button to select the Diode Test range.
The meter automatically defaults to Resistance.
3. Insert the red test lead into the “V Ω TEMP HZ” input terminal
and the black lead to the “COM” terminal.
4. Connect the other end of the test leads to the component under test.
Read the display.
Notes:
• Usethediodetesttocheckdiodes,transistors,siliconcontrolled
rectiers(SCR’s)andothersemiconductordevices
• Thetestsendsacurrentthroughasemiconductorjunction,
thenmeasuresthejunction’svoltagedrop.
• Normalforwardvoltagedrop(forwardbias)foragoodsilicondiode
is between 0.4V to 0.9V. A reading higher than that indicates a leaky
(defective)diode.Azeroreadingindicatesashorteddiode.
• Reversethetestleadsconnection(reversebias)acrossthediode.
The display shows “OL” if the diode is good. Any other readings
indicatethediodeisshortedorresistive(Defective).

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Continuity Testing
1. Set the function switch to range position.
2. Press the MODE button to select the Continuity Test range.
The meter automatically defaults to Resistance.
3. Insert the red test lead into the “V Ω TEMP HZ” input terminal
and the black lead to the “COM” terminal.
4. Short the tip of the test leads and make sure the display reads “0”
and the buzzer beeps.
5. Connect the tip of the test leads to the circuit or component under
test. The display reads the resistance and the buzzer beeps when the
 readingisnotmorethanabout35Ω.
Notes:
• Using resistance and continuity function in a live circuit will produce
false results and may damage the instrument.
• In may cases the suspicious components must be disconnected from
the circuit under test to obtain accurate results.
• WARNINGbeforeattemptingtomakeatest,ensurethereisno
voltage present on the circuit.

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Data Hold
Thisisafunctionusedtofreezethereadingonthedisplay,
ideal for later viewing.
1. Press the HOLDbuttononce.WhentheHoldisactivated,themeter
beeps,freezesthereading,anddisplaysthe“HOLD” indicator on
the LCD.
2. To deactivate the “HOLD”function,pressHOLDbuttononce,the
meter will beep and the meter will start reading a new measurements.
Peak Hold
This is a function used to record the maximum and minimum readings on
the display for the voltage and current ranges.
1. Press the PEAK button once. This will record The “PEAK”maximum,
themeterbeeps,anddisplaythe“P MAX” indicator on the LCD.
2. Press the PEAK button again. This will record the “PEAK”maximum,
themeterbeeps,anddisplaythe“P MIN” indicator on the LCD.
3. To deactivate the “PEAK”function,pressthebuttonfor3seconds,the
meter will beep and the meter will start reading new measurements.
LCD Backlight
The backlight is ideally used in dark or dimly lit areas.
1. Press the buttonfor3seconds,andthebrightwhitelight
will come on.
2. To turn off the backlight press the button for 3 seconds.
Note: The use of the backlight will reduce the battery life considerably.
ForserviceonthisoranyotherREEDproduct,contactREEDInstruments
at [e-mail].

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Auto Power Off
This feature automatically turns off the meter after approximately
20minutesfromthelastmeasurementtaken.Toturnthemeterbackon,
press any button or move the rotary switch to any position. Ensure the
test leads are disconnected from any circuit to avoid injury or damage to
the meter.
Battery Replacement
When the signappearsontheLCD,thisindicatesthebattery
should be replaced. Use the following procedure to replace the standard
9Vbattery(IEC6F22)battery.
1. Disconnect the test leads from any live source and remove
the leads from the input terminals.
2. Rotate the function switch to the OFF position.
3. The battery cover is secured to the bottom of the case by a screw.
Using a screwdriver remove the screw from the battery cover and
remove the battery cover from the meter.
4. Remove the old battery and replace it with a new
IEC 6F 22 9V battery.
5. Replace the battery cover
and reinstall the screw.
Battery Cover

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