CEM DT-6505 User manual

User's Guide
The Industrial Multimeter

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Introduction
This meter measures AC/DC Voltage, AC/DC Current, Resistance,
Capacitance, Frequency (electrical & electronic), Duty Cycle, Diode
Test,Insulation Test, and Continuity plus Thermocouple Temperature. It
can store and recall data. It features a waterproof, rugged design for
heavy duty use. Proper use and care of this meter will provide many
years of reliable service.
Safety
This symbol adjacent to another symbol, terminal or o
perating device indicates that the operator must refer t
o an explanation in the Operating Instructions to avoid
personal injury or damage to the meter.
This WARNING symbol indicates a potentially hazard
ous situation, which if not avoided, could result in deat
h or serious injury.
This CAUTION symbol indicates a potentially hazardo
us situation, which if not avoided, may result damage t
o the product.
This symbol advises the user that the terminal(s) so m
arked must not be connected to a circuit point at whic
h the voltage with respect to earth ground exceeds (in
this case) 1000 VAC or VDC.
This symbol adjacent to one or more terminals identifi
es them as being associated with ranges that may, in
normal use, be subjected to particularly hazardous vol
tages. For maximum safety, the meter and its test lead
s should not be handled when these terminals are ene
rgized.
This symbol indicates that a device is protected throug
hout by double insulation or reinforced insulation.
PER IEC1010 OVERVOLTAGE INSTALLATION CATEGORY
WARNING
CAUTION
MAX
1000V

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OVERVOLTAGE CATEGORY I
Equipment of OVERVOLTAGE CATEGORY I is equipment for
connection to circuits in which measures are taken to limit the transient
overvoltages to an appropriate low level.
Note – Examples include protected electronic circuits.
OVERVOLTAGE CATEGORY II
Equipment of OVERVOLTAGE CATEGORY II is energy-consuming
equipment to be supplied from the fixed installation.
Note – Examples include household, office, and laboratory appliances.
OVERVOLTAGE CATEGORY III
Equipment of OVERVOLTAGE CATEGORY III is equipment in fixed
installations.
Note – Examples include switches in the fixed installation and some
equipment for industrial use with permanent connection to the fixed
installation.
OVERVOLTAGE CATEGORY IV
Equipment of OVERVOLTAGE CATEGORY IV is for use at the origin
of the installation.
Note – Examples include electricity meters and primary over-current prot
ection equipment
SAFETY INSTRUCTIONS
This meter has been designed for safe use, but must be operated with
caution. The rules listed below must be carefully followed for safe
operation.
1. NEVER apply voltage or current to the meter that exceeds the
specified maximum:

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Input Protection Limits
Function
Maximum Input
V DC or V AC
1000VDC/AC rms
mA AC/DC
500mA 1000V fast acting fuse
A AC/DC
10A 1000V fast acting fuse (20A
for 30 seconds max every 15
minutes)
Frequency, Resistance, Cap
acitance, Duty Cycle, Diode T
est, Continuity
1000VDC/AC rms
Temperature
1000VDC/AC rms
Surge Protection: 8kV peak per IEC 61010
2. USE EXTREME CAUTION when working with high voltages.
3. DO NOT measure voltage if the voltage on the "COM" input jack
exceeds 1000V above earth ground.
4. NEVER connect the meter leads across a voltage source while the
function switch is in the current, resistance, or diode mode. Doing so
can damage the meter.
5. ALWAYS discharge filter capacitors in power supplies and
disconnect the power when making resistance or diode tests.
6. ALWAYS turn off the power and disconnect the test leads before
opening the covers to replace the fuse or batteries.
7. NEVER operate the meter unless the back cover and the battery
and fuse covers are in place and fastened securely.
If the equipment is used in a manner not specified by the manufactur
er, the protection provided by the equipment may be impaired.

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Controls and Jacks
1. mA, µA , temp ,INS and Rlow input jacks
2. 10A input jacks
3. 50,000 count LCD display
4. STORE(VIEW) button
5. TIME/PI/DAR(RANGE/DOWN) button
6. MODE(BLUE) button
7. INSULATION TEST button
8. INSULATION LOCK button
9. COM input jack
10. Input Terminal to operate the
switched probe
11. Positive input jack
12. REL button
13. MAX/MIN(PEAK/DOWN) button
14. HOLD/Backlight/DEL button
15. Function switch
Note: Tilt stand and battery compartment are on rear of unit.

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Symbols and Annunciators
•))) Continuity
Diode test
Battery status
n nano (10-9)
(capacitance)
µ micro (10-6) (amps,
cap)
m milli (10-3) (volts,
amps)
A Amps
k kilo (103) (ohms)
F Farads (capacitance)
M mega (106) (ohms)
Ohms PEAK Peak Hold
Hz Hertz (frequency) V Volts
% Percent (duty ratio) REL Relative
AC Alternating current AUTO Autoranging
DC Direct current HOLD Display hold
ºF Degrees Fahrenheit ºC Degrees Centigrade
MAX Maximum MIN Minimum
AC +DC Alternating current + Direct current
TRMS Ture RMS
LOG Store
VIEW Recall
AUTO Auto Range
Resistance low operator indication
Bluetooth
Low pass filtering
Timing symbol
Backlight
bargraph

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Operating Instructions
WARNING: Risk of electrocution. High-voltage circuits, both AC and DC,
are very dangerous and should be measured with great care.
1. ALWAYS turn the function switch to the OFF position when the
meter is not in use.
2. If “OL” appears in the display during a measurement, the value
exceeds the range you have selected. Change to a higher range.
DC VOLTAGE MEASUREMENTS
CAUTION: Do not measure DC voltages if a motor on the circuit is
being switched ON or OFF. Large voltage surges may occur that can
damage the meter.
1. Set the function switch to the position.
2. Press the MODE button to indicate “DC”.
3. Insert the black test lead banana plug into the
negative COM jack.
Insert the red test lead banana plug into the
positive Vjack.
4. Touch the black test probe tip to the negative
side of the circuit.
Touch the red test probe tip to the positive side
of the circuit.
5. Read the voltage in the display.

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AC VOLTAGE (FREQUENCY, DUTY CYCLE) MEASUREMENTS
WARNING: Risk of Electrocution. The probe tips may not be long
enough to contact the live parts inside some 240V outlets for
appliances because the contacts are recessed deep in the outlets. As
a result, the reading may show 0 volts when the outlet actually has
voltage on it. Make sure the probe tips are touching the metal
contacts inside the outlet before assuming that no voltage is present.
CAUTION: Do not measure AC voltages if a motor on the circuit is
being switched ON or OFF. Large voltage surges may occur that can
damage the meter.
1. Set the function switch to the position.
2. Press the MODE button to indicate “AC”.
3. Insert the black test lead banana plug into the
negative COM jack.
Insert red test lead banana plug into the
positive Vjack.
4. Touch the black test probe tip to the neutral
side of the circuit.
Touch the red test probe tip to the “hot” side
of the circuit.
5. Read the voltage in the display.
6. Press the MODE button to indicate “Hz(%)”.
7. Read the frequency in the main display and
the duty in the auxiliary display .

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MV VOLTAGE MEASUREMENTS
CAUTION: Do not measure mV voltages if a motor on the circuit is
being switched ON or OFF. Large voltage surges may occur that can
damage the meter.
1. Set the function switch to the mV position.
2. Press the MODE button to indicate “DC”or
“AC ”.
3. Insert the black test lead banana plug into
the negative COM jack.
Insert the red test lead banana plug into
the
positive Vjack.
4. Touch the black test probe tip to the
negative side of the circuit.
Touch the red test probe tip to the positive
side of the circuit.
5. Read the mV voltage in the display.

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DC CURRENT MEASUREMENTS
CAUTION: Do not make 20A current measurements for longer than
30 seconds. Exceeding 30 seconds may cause damage to the meter
and/or the test leads.
1. Insert the black test lead banana plug into
the negative COM jack.
2. For current measurements up to 5000µA
DC, set the function switch to the µA
position and insert the red test lead
banana plug into the µA/mA jack.
3. For current measurements up to 400mA
DC, set the function switch to the mA
position and insert the red test lead
banana plug into the µA/mA jack.
4. For current measurements up to 20A DC,
set the function switch to the 10A/HZ/%
position and insert the red test lead
banana plug into the 10A jack.
5. Press the MODE button to indicate “DC”
on the display.
6. Remove power from the circuit under test,
then open up the circuit at the point where
you wish to measure current.
7. Touch the black test probe tip to the
negative side of the circuit.
Touch the red test probe tip to the
positive side of the circuit.
8. Apply power to the circuit.
9. Read the current in the display.

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AC CURRENT (FREQUENCY, DUTY CYCLE) MEASUREMENTS
CAUTION: Do not make 20A current measurements for longer than
30 seconds. Exceeding 30 seconds may cause damage to the meter
and/or the test leads.
1. Insert the black test lead banana plug into
the negative COM jack.
2. For current measurements up to 5000µA
AC, set the function switch to the yellow
µA position and insert the red test lead
banana plug into the µA/mA jack.
3. For current measurements up to 500mA
AC, set the function switch to the mA
position and insert the red test lead
banana plug into the µA/mA jack.
4. For current measurements up to 20A AC,
set the function switch to the yellow
10A/HZ/% position and insert the red test
lead banana plug into the 10A jack.
5. Press the MODE button to indicate “AC”
on the display.
6. Remove power from the circuit under test,
then open up the circuit at the point where
you wish to measure current.
7. Touch the black test probe tip to the
neutral side of the circuit.
Touch the red test probe tip to the “hot” side of the circuit.
8. Apply power to the circuit.
9. Read the current in the display.
10. In the 10A and mA function ,press the MODE button to indicate
“Hz(%)”.
11. Read the frequency in the main display and the duty in the auxiliary
display .

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RESISTANCE MEASUREMENTS
WARNING: To avoid electric shock, disconnect power to the unit
under test and discharge all capacitors before taking any resistance
measurements. Remove the batteries and unplug the line cords.
1. Set the function switch to the position.
2. Insert the black test lead banana plug into the
negative COM jack.
Insert the red test lead banana plug into the positive
jack.
3. Press the MODE button to indicate “”on the
display.
4. Touch the test probe tips across the circuit or part
under test. It is best to disconnect one side of the
part under test so the rest of the circuit will not
interfere with the resistance reading.
5. Read the resistance in the display.
CONTINUITY CHECK
WARNING: To avoid electric shock, never measure continuity on
circuits or wires that have voltage on them.
1. Set the function switch to the position.
2. Insert the black lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive jack.
3. Press the MODE button to indicate“ " and “Ω” on the display
4. Touch the test probe tips to the circuit or wire you wish to check.
5. If the resistance is less than approximately 50, the audible signal
will sound. If the circuit is open, the display will indicate “OL”.

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DIODE TEST
1. Set the function switch to the green Ω CAP
position.
2. Insert the black test lead banana plug into the
negative COM jack and the red test lead
banana plug into the positive Vjack.
3. Press the MODE button to indicate“ “ and “V”
on the display.
4. Touch the test probes to the diode under test.
Forward voltage will typically indicate 0.400 to
0.700V. Reverse voltage will indicate “OL”.
Shorted devices will indicate near 0V and an
open device will indicate “OL” in both polarities.
CAPACITANCE MEASUREMENTS
WARNING: To avoid electric shock, disconnect power to the unit
under test and discharge all capacitors before taking any capacitance
measurements. Remove the batteries and unplug the line cords.
1. Set the rotary function switch to the green Ω
CAP position.
2. Insert the black test lead banana plug into the
negative COM jack.
3. Insert the red test lead banana plug into the
positive Vjack.
4. Press the MODE button to indicate “F”
5. Touch the test leads to the capacitor to be
tested.
Read the capacitance value in the
Display

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TEMPERATURE MEASUREMENTS
1. Set the function switch to the green
Temp position.
2. Insert the Temperature Probe into the
input jacks, making sure to observe
the correct polarity.
3. Press the MODE button to indicate “ºF”
or “ºC”
4. Touch the Temperature Probe head to
the part whose temperature you wish to
measure. Keep the probe touching the
part under test until the reading
stabilizes (about 30 seconds).
5. Read the temperature in the display.
Note: The temperature probe is fitted with a type K
mini connector.
A mini connector to banana connector adaptor
is supplied for
connection to the input banana jacks.
FREQUENCY (DUTY CYCLE) MEASUREMENTS (ELECTRONIC)
1. Set the rotary function switch to the green Hz/%
position.
2. Insert the black lead banana plug into the
negative COM jack and the red test lead
banana
plug into the positive Hz jack.
3. Touch the test probe tips to the circuit under test.
4. Read the frequency on the display.
5. Press the MODE button to indicate “%”.
6. Read the % duty cycle in the display.

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INSULATION RESISTANCE MEASUREMENTS
a) Set the rotary function switch to the INSULATION position, and Press t
he RANGE button to chose one of the voltage which
display on the left .
b)Connect two testing lines to the tested；
c)Push down and hold the “TEST” button /or press the “ LOCK” key
stoke first and then the “TEST” button, if the tested is electriferous and its
voltage ( AC/DC) is over 30V, it will refuse work and no high-voltage te
sting occurs, if the tested is diselectriferous or its voltage is
lower than 30V, it will enter into the formal testing process and brings
the high-voltage. on the primary display, the insulation resistance
in MΩ is indicated in-phase with analog bar; on the auxiliary display,
the tested insulation voltage in V (DC) is indicated, the symbol “ ” flas
hes and the buzzer warns frequently
d)Being free from the “TEST” button or pushing down the “TEST”
button in the “LOCK “ status can exit from the “LOCK” status and shutoff t
he high-voltage，synchronously, the resistance values is indicated in th
e primary display will be held, and the auxiliary display still be in the sta
tus of monitoring the insulation voltage for the tested .
e)Subsequently, discharge the balance insulation voltage of the tested thr
ough the inner switch of the meter.
POWER TOOLS AND AMALL APPLIANCES
This test would also apply to other similar equipment that has a line cord.
For double insulated power tools, the megohmmeter lead shown connect
ed to the housing would be connected to some metal part lf the tool(e..g c
huck,blade).
Note:The switch of the device must be in the “ON”position and the main p
ower should be disconnected.

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MOTORS
AC-Disconnect the motor from the line by disconnecting the wires at the
motor terminals or by opening the main switch. If the main switch is used
and the motor also has a starter then the starter must be held, by some
means, in the “ON” position. In the latter case, the measured resistance
will include the resistance of the motor, wire and all other components bet
ween the motor and the main switch. If a weakness is in dicated, the mot
or and other components should be checked individually. If the motor is di
sconnected at the motor terminals, connect one megohmmeter lead to th
e grounded motor housing and the other lead to One of the motor leads.
DC-Disconnect the motor from the line. To test the brush rigging,field coil
s and armature connect one megohmmeter lead to the grounded motor h
ousing and the other lead to the brush on the commutator. If the resistanc
e measurement indicates a weakness,raise the brushes off the commutat
or and separately test the armature, field coils and brush rigging by conne
cting one megohmmeter lead to each of them individually, leaving the oth
er connected to the grounded motor housing. The above also applies to
DC Gemerators.

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CABLES
Disconnect the cable from the line. Also disconnect opposite end to avoid
errors due to leakage from other equipment. Check each conductor to gr
ound and /or lead sheath by connecting one megohmmeter lead to a grou
nd and /or lead sheather and the other megohmmeter lead to each of the
conductors in turn. Check insulation resistance between conductors by co
nnecting megohmmeter leads to conductors in pairs.

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AUTORANGING/MANUAL RANGE SELECTION
When the meter is first turned on, it automatically goes into
AutoRanging. This automatically selects the best range for the
measurements being made and is generally the best mode for most
measurements. For measurement situations requiring that a range be
manually selected, perform the following:
1. Press the RANGE key. The “AUTO” display indicator will turn off.
2. Press the RANGE key to step through the available ranges until you
select the range you want.
3. To exit the Manual Ranging mode and return to Autoranging, press
and hold RANGE button.
MAX/MIN
1. Press the MAX/MIN key to activate the MAX/MIN recording mode.
The display icon "MAX" will appear. The meter auxiliary display will
display and hold the maximum reading and will update only when a
new “max” occurs.at the same time the minimum values are
calculated as well,press the MAX/MIN button to alternately display
the maximum or minimum values.
2.To exit MAX/MIN mode press and hold the MAX/MIN button about
two seconds.
RELATIVE MODE
The relative measurement feature allows you to make measurements
relative to a stored reference value. A reference voltage, current, etc.
can be stored and measurements made in comparison to that value.
The displayed value is the difference between the reference value and
the measured value. Note: Relative mode operate in the Rlow
function is zero.
1. Perform the measurement as described in the operating instructions.
2. Press the REL button to store the reading in the display and the
"REL" indicator will appear on the display.
3. the auxiliary display show REL TEST value and Main display show
the current value.
4. Press the REL button to exit the relative mode.

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Display Backlight
Press the button to turn the backlight on or off. The backlight
will automatically turn off after 30 SECONDS. Press and hold the
button to switch backlight mode.
HOLD
The hold function freezes the reading in the display. Press the HOLD
key momentarily to activate or to exit the HOLD function.
PEAK HOLD
The Peak Hold function captures the peak voltage or current.
The meter can capture negative or positive peaks as fast as 1
millisecond in duration. Press and hold about two seconds the PEAK
button, “PEAK” and “MAX” will display. Press it again," MIN” will
display but “MAX”will disappear. The meter will update the dispay each
time a lower negative peak and a higher positive voltage occurs.
Press and hold the button to exit the PEAK HOLD mode. Auto
Power Off feature will be disabled automatically in this mode.
Data record（STORE/RECALL ）
1、LOG/VIEW function
In the normal testing mode, press and hold STORE/VIEW button abo
ut two seconds into STORE OR WIEW function sequence, such as,
manual LOG->TIME SET FOR auto LOG->auto LOG->VIEW
IN manual LOG function,press the STORE/VIEW button once can store