Delton 770E User manual

770E
DIGITAL MULTIMETER
OPERATOR’S MANUAL

TABLE OF CONTENTS
1.Overview ...................................................................................... 1
2.Panel Layout..............................................................................1/2
3.Safety information.......................................................................2
4.Specical cautions for operation................................................... 2
5.General specifications...............................................................2/3
6.Testing specifications................................................................3/5
6.1 DC current. ........................................................................... 3
6.2 AC Voltage (True RMS).......................................................... 3
6.3 DC current. ............................................................................ 3
6.4 AC Current (True RMS).......................................................... 4
6.5 Resistance ............................................................................. 4
6.6 Capacitance........................................................................... 4
6.7 Frequency.............................................................................. 4
6.8 Duty cycle .............................................................................. 5
6.9 Temperature. .............................................................................. 5
6.10 Diode and Audible continuity test.......................................... 5
6.11 Transistor hFE test............................................................. 5
6.12 Non Contact AC Voltage (NCV) detection............................. 5
7.Operating instructions...............................................................5/8
7.1 Attention before operation...................................................... 5
7.2 Measuring DC & AC Voltage. ................................................... 5
7.3 Measuring DC & AC Current.................................................. 6
7.4 Measuring Resistance............................................................ 6
7.5 Measuring Capacitance.......................................................... 7
7.6 Measuring Frequency & Duty cycle........................................ 7
7.7 Measuring Temperature............................................................. 7
7.8 Diode & Audible continuity Testing ...............................................7
7.9 Transistor hFE test.................................................................. 8
7.10 Non contact AC Voltage detection. .......................................... 8
8.Battery replacement..................................................................... 8
9.Fuse replacement........................................................................ 8
10.Maintenance. ............................................................................. 9
11.Accessories................................................................................ 9

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1. Overview
The multimeter is characterized at slim size, portable, stable performance and anti-dropping
capacity. Using 40000 counts digit & analogue bar graph LCD monitor with character 16.5mm
high, they offer clear readings. With overall circuitry design centering on large-scale IC A/D
converters in conjunction and over-load protection circuit, the meters give excellent
performance and exquisite making as a handy utility instrument.
The meters can be used to measure DC & AC voltage, DC & AC current, resistance, capacitor,
frequency, duty cycle, temperature, transistor hFE, Non Contact AC Voltage (NCV) detection,
positive diode voltage fall and audible continuity.
2. Panel Layout
①NCV detection area: Non Contact AC Voltage (NCV) detection area.
②CDS sensor: The CDS sensor can reaction to the ambient brightness range, then
automatically control the LCD backlight to lighten or go out.
③NCV red light: Non Contact AC Voltage (NCV) detection red light.
④NCV green light: Non Contact AC Voltage (NCV) detection green light.
⑤LCD display: 40000 counts digit & analogue bar graph, full function symbol display.
⑥SELECT key: This key work on the " " range, press the key to choose
resistance, diode or continuity test, on the voltage or current range, change to DC or AC,
on the range, change to ℃or ℉test; If press and hold SELECT key to power on,
“Auto Power Off ”function will be disabled.
⑦RANGE Key: Press the “RANGE”key, the meter enters manual range mode, press it
more than 2 seconds again, return to auto mode.
⑧REL▲Key: Press the “REL▲”key, the meter enters relative measuring mode, “REL”
is displayed on the LCD and the present reading becomes the reference value and
displayed on the display. Relative measurement REL△=measurement value-Reference
value. Press it again to exit.
⑨Hz/Duty Key: On “ACV/ACA” or “Hz” range, press the “Hz/Duty”key, you can choose
the Frequency or Duty Cycle measurement.

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⑩HOLD key: Press the “HOLD”key to lock display value, and the “DH”sign will appear
on the display, press it again to exit.
⑪MAX/MIN key: Press the “MAX/MIN”key to lock MAX or MIN value, and the “MAX”or
“MIN”sign will appear on the display, press it over 2 seconds to exit.
⑫Rotary Switch: Use this switch to select functions and ranges.
⑬μAmAT+: μAmAandTemperature “+”InputJack
⑭20A:20AInputJack
⑮VΩHz : V/Hz/ InputJack
⑯COMT-:COMand Temperature “-”InputJack
⑰Transistor hFE test InputJack
⑱Crust of meter
⑲Protective casing
3. Safety Information
3-1 The meter is designed according to IEC-1010 concerning electronic measuring
instruments with an over-voltage category 1000V (CAT Ⅲ) and pollution 2.
3-2 Follow all safety and operating instructions to ensure that the meter is used safely and is
kept in good operating condition.
3-3 safety symbols:
Important safety information, refer to the operating manual.
Dangerous voltage may be presence.
Double insulation (protection Class II)
4. Special Cautions for Operation
4-1 The meters can be safe only according to standard procedures when used in conjunctions
with the supplied test leads. To replace damaged test leads with only the same model or same
electric specifications.
4-2 To avid risk of electric shock, do not use the meters before the cover is in place.
4-3 The range switch should be right position for the testing.
4-4 To avoid electric shock and damaging the instruments, the input signals are forbidden to
exceed the specified limits.
4-5 When measuring TV set or switched power, attention should be paid to the possible pulses
that may bring destruction to the circuit.
4-6 Range switch position is forbidden to be changed at random during measurement.
4-7 Take caution against shock in the course of measuring voltage higher than DC 60V & AC
30V.
4-8 Protection fuse should be replaced only with same type and same specification.
4-9 After operation is finished, set function switch at OFF to save battery power.
4-10 If the meter is without usage for long time, take out battery to avoid damage by battery
leakage.
5. General specifications
5-1 Max Voltage between input terminal and Earth Ground: CAT Ⅲ1000V
5-2 Over-range Indication: display “OL” for the significant digit.
5-3 Automatic display of negative polarity “-”.

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5-4 Low Battery Indication: “ ” displayed.
5-5 Max LCD display: 40000 counts digit & analogue bar graph.
5-6 Auto range & Manual range control
5-7Auto Power Off: When measurement exceeds 15 minutes without switching mode and
pressing key, the meter will switch to standby mode. Press any key to exit standby mode.
When restart the system, press and hold SELECT key to disable auto power off.
5-8 Auto LCD backlight
5-9 Fuse protection: 500mA/500V Fast Fuse, 20A/500V Fast Fuse
5-10 Power supply: 9V 6F22 battery.
5-11 Operating temperature: 0°C~40°C (max. 80% RH).
5-12 Storage temperature: -20°C~60°C (max. 90% RH).
6-1 DC Voltage
Range
Resolution
Accuracy
40mV
1μV
±(0.5% of rdg + 5 digits)
400mV
10μV
±(0.05% of rdg + 2 digits)
4V
100μV
40V
1mV
400V
10mV
1000V
100mV
±(0.05% of rdg + 5 digits)
-- Impedance: 10MΩ, More than 100MΩ on 40mV/400mV range
-- Overload protection: 1000V DC or 750V AC rms
6-2 AC Voltage (True RMS)
-- Impedance: 10MΩ, More than 100MΩ on 40mV/400mV range
-- Overload protection: 1000V DC or 750V AC rms
-- Frequency Range: 40 to 1kHz
6-3 DC Current
Range
Resolution
Accuracy
400μA
0.01μA
±(1.0% of rdg + 5 digits)
4000μA
0.1μA
40mA
1μA
400mA
10μA
4A
100μA
±(1.2% of rdg + 10 digits)
20A
1mA
Range
Resolution
Accuracy
40mV
1μV
±(1.0% of rdg + 10 digits)
400mV
10μV
±(0.8% of rdg + 10 digits)
4V
100μV
40V
1mV
400V
10mV
750V
100mV
±(1.2% of rdg + 10 digits)
6.Testing specifications

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-- Overload protection: 500mA/500V Fast Fuse, 20A/500V Fast Fuse, 20A up to 10 seconds
6-4 AC Current (True RMS)
Range
Resolution
Accuracy
400μA
0.01μA
±(1.2% of rdg + 10 digits)
4000μA
0.1μA
40mA
1μA
400mA
10μA
4A
100μA
±(1.5% of rdg + 10 digits)
20A
1mA
-- Overload protection: 500mA/500V Fast Fuse, 20A/500V Fast Fuse, 20A up to 10 seconds
-- Frequency Range: 40 to 400Hz
6-5 Resistance
Range
Resolution
Accuracy
400Ω
0.01Ω
±(1.0% of rdg + 10 digits)
4kΩ
0.1Ω
±(0.2% of rdg + 10 digits)
40kΩ
1Ω
400kΩ
10Ω
4MΩ
100Ω
40MΩ
1kΩ
±(0.5% of rdg + 10 digits)
-- Overload protection: 500V DC or AC rms
6-6 Capacitance
Range
Accuracy
Resolution
9.999nF
±(5.0% of rdg + 10 digits)
1pF
99.99nF
±(3.0% of rdg + 10 digits)
10pF
999.9nF
±(2.5% of rdg + 5 digits)
100pF
9.999µF
1nF
99.99µF
±(5.0% of rdg + 10 digits)
10nF
999.9µF
±(10.0% of rdg + 20 digits)
100nF
9.999mF
1µF
99.99mF
10µF
-- Overload protection: 500V DC or AC rms
6-7 Frequency
Range
Accuracy
Resolution
9.999Hz
± (0.1% of rdg + 5 digits)
0.001Hz
99.99Hz
0.01Hz
999.9Hz
0.1Hz
9.999kHz
1Hz
99.99kHz
10Hz
999.9kHz
100Hz
9.999MHz
1kHz
-- Sensitivity: sine wave 0.6V rms (9.999MHz: 1.5V rms)

5
-- Overload protection: 500V DC or AC rms
6-8 Duty cycle
0.1%～99.9%: ± ( 2.0% of rdg + 2 digits ), Frequency lower than 10kHz
-- Sensitivity: sine wave 0.6V rms
-- Overload protection: 500V DC or AC rms
6-9 Temperature
Range
Accuracy
Resolution
℃
-20~150℃
± ( 3℃+ 3digits )
0.1℃
150~1000℃
± ( 3% of rdg + 3digits )
℉
-4~302℉
± ( 5℉+ 5digits )
0.1℉
302~1832℉
± ( 3% of rdg + 5digits )
-- NiCr-NiSi K-type sensor
-- Overload protection: 500mA/500V Fast Fuse
6-10 Diode and Audible continuity test
Range
Description
Test Condition
Display read approximately
forward voltage of diode
Forward DC current
approx. 1.5mA
Reversed DC voltage
approx. 3.2V
Built-in buzzer sounds if
resistance is less than 50Ω
Open circuit voltage
approx. 1V
Overload protection: 500V DC or AC rms
6-11 Transistor hFE test
Test range: 0-1000
Ib=10µA, Vce=1.8V Approx.
6-12 Non Contact AC Voltage (NCV) detection
Test voltage range: 90V～1000V AC rms
The NCV red light and green light will light up alternately together with sound.
7. Operating instructions
7-1 Attention before operation
7-1-1 Check battery. When the battery voltage drop below proper operation range, the “ ”
symbol will appear on the LCD display and the battery need to changed.
7-1-2 Pay attention to the “ ” besides the input jack which shows that the input voltage or
current should be within the specified value.
7-1-3 The range switch should be positioned to desired range for measurement before
operation.
7-2 Measuring DC & AC Voltage

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7-2-1 Set the rotary switch at the desired “mV ”or “V”range position, it shows symbol
for testing DC voltage, if you want to test AC voltage, push “SELECT” button switch.
7-2-2 Connect the black test lead to COMT- jack and the red to VΩHz jack.
7-2-3 Connect test leads across the source or load under measurement.
7-2-4 You can get reading from LCD. The polarity of the red lead connection will be indicated
along with the DC voltage value.
NOTE:
1.“ ” means you can’t input the voltage more than 1000V DC or 750V AC, it’s possible to
show higher voltage, but it may destroy the inner circuit or pose a shock.
2. Be cautious against shock when measuring high Voltage.
7-3 Measuring DC & AC Current
7-3-1 Set the rotary switch at the desired “uA ”& “mA ”& “A”range position, it
shows symbol for testing DC current, if you want to test AC current, push “SELECT” button
switch.
7-3-2 Connect the black test lead to COMT- jack and the red to the μAmAT+ jack for a
maximum 400mA current , for a maximum 4A or 20A current, move the red lead to the 20A
jack.
7-3-3 Connect test leads in series with the load under measurement.
7-3-4 You can get reading from LCD. The polarity of the red lead connection will be indicated
along with the DC current value.
NOTE:
1. When the value scale to be measured is unknown beforehand, set the range selector at the
highest position.
2. When only “OL” is displayed, it indicates over-range situation and the higher range has to
be selected.
3. “ ” means the socket mA’s maximum current is 500mA and 20A’s maximum current is
20A, over 500mA or 20A current can be protected by the fast fuse.
4. On the 20A range, the measuring time should be less than 10 seconds to prevent precision
from affecting by circuit heating.
7-4 Measuring Resistance
7-4-1 Set the rotary switch at the desired “ ” range position.
7-4-2 Connect the black test lead to COMT- jack and the red to VΩHz jack.
7-4-3 Connect test leads across the resistance under measurement.
7-4-4 You can get reading from LCD.
NOTE: Max. input overload: 500V rms＜10sec
1. For measuring resistance above 1MΩ, the mete may take a few seconds to get stable
reading.
2. When the input is not connected, i.e. at open circuit, the figure ‘OL’ will be displayed for the

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over-range condition.
3. When checking in-circuit resistance, be sure the circuit under test has all power removed
and that all capacitors have been discharged fully.
7-5 Measuring Capacitance
7-5-1 Set the rotary switch at the desired “ ” range position.
7-5-2 Connect the black test lead to COMT- jack and the red to VΩHz jack.
7-5-3 Connect test leads across the capacitance under measurement.
7-5-4 You can get reading from LCD.
NOTE: Max. input overload: 500V rms＜10sec
1. Capacitors should be discharged before being tested.
2. When testing large capacitance, it will take longer time before the final indication ( For
100uF~99.99mF range, it will take about 10 seconds ).
3. When testing small capacitance (≤1uF), to assure the measurement accuracy, first press
"REL▲", then go on measuring.
7-6 Measuring Frequency & Duty cycle
7-6-1 Set the rotary switch at the desired “Hz”range position.
7-6-2 Connect the black test lead to COMT- jack and the red to VΩHz jack.
7-6-3 Push “Hz/Duty”key to choose Frequency or Duty cycle test.
7-6-4 Connect the probe across the source or load under measurement.
7-6-5 You can get reading from LCD.
7-7 Measuring Temperature
7-7-1 Set the rotary switch at the desired “ ” range position, push “SELECT” to choose ℃
or ℉ measurement.
7-7-2 Connect the black banana plug of the sensor to COMT- jack and the red banana plug to
the μAmAT+ jack.
7-7-3 Put the sensor probe into the temperature field under measurement.
7-7-4 You can get reading from LCD.
NOTE:
1. The accessory of the meter WRNM-010 type contact thermocouple limit temperature is
250 ℃(300 ℃shortly), please use special probe for test higher temperature.
2. Please don't change the thermocouple at will, otherwise we can't guarantee to measure
accuracy.
3. Please don’t importing the voltage in the temperature function.
7-8 Diode & Audible continuity Testing
7-8-1Set the rotary switch at the “ ” range position, push “SELECT” to choose Diode
or Audible continuity measurement.
7-8-2 Connect the black test lead to COMT- jack and the red to VΩHz jack.
7-8-3 On diode range, connect the test leads across the diode under measurement, display

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shows the approx. forward voltage of this diode.
7-8-4On Audible continuity range, connect the test leads to two point of circuit, if the
resistance is lower than approx. 50Ω, the buzzer sounds.
NOTE: Make sure the power is cut off and all capacitors need to be discharged under this
measurement.
7-9 Transistor hFE Test
7-9-1Set the rotary switch at the desired “hFE”range position.
7-9-2Determine whether the transistor is NPN or PNP and locate the Emitter, Base and
Collector leads. Insert the leads into the proper holes in the socket on the front panel.
7-9-3 You can get reading of the approximate hFE value from LCD.
NOTE: Don’t connect an external voltage to measuring terminals.
7-10 Non Contact AC Voltage detection
7-10-1Set the rotary switch at the desired “NCV”range position, the NCV green LED light will
light up.
7-10-2Hold the Meter so that the mater’s top is vertically and horizontally centered and
contacting the conductor, when the live voltage ≥90V AC rms, the NCV red LED light
and green LED light will light up alternately together with sound.
NOTE:
1. Even without LED indication, the voltage may still exist. Do not rely on non-contact voltage
detector to determine the presence of voltage wire. Detection operation may be subject to
socket design, insulation thickness and different type and other factors.
2. When the meter input terminals presence voltage, due to the influence of presence voltage,
voltage sensing indicator may also be bright.
3. Keep the meter away from electrical noise sources during the tests, i.e., florescent lights,
dimmable lights, motors, etc.. These sources can trigger Non-Contact AC Voltage detection
function and invalidate the test.
8. Battery replacement
8-1 When the battery voltage drop below proper operation range the " " symbol will appear
on the LCD display and the battery need to changed.
8-2 Before changing the battery, set the selector switch to “OFF”position and remove the test
leads from the terminals. Open the cover of the battery cabinet by a screwdriver.
8-3 Replace the old battery with the same type battery (9V 6F22).
8-4 Close the cover of the battery cabinet and fasten the screw.
9. Fuse replacement
9-1 This meter is provided with a 500mA/500V fast fuse to protect the temperature test and the
current measuring circuits which measure up to 400mA, with a 20A/500V fuse to protect the
20A range.
9-2 Ensure the meter is not connected to any external circuit, set the selector switch to “OFF”

position and remove the test leads from the terminals. Open the cover of the battery cabinet
by a screwdriver.
9-3 Replace the old fuse with the same type and rating: 6×30mm 500mA/500V fast fuse or
6×30mm 20A/500V fast fuse.
9-4 Close the cover of the battery cabinet and fasten the screw.
10. Maintenance
10-1 You must replace the test leads if the lead is exposed, and should adopt the leads with
the same specifications as origin.
10-2 Use only moist fabric or small amount of detergent but not chemical solution for cleaning.
10-3 Do not use the meter before the back cover is properly closed and screw secured. Upon
any abnormality, stop operation immediately and send the meter for maintenance.
10-4 Please take out the battery when not using for a long time.
11. Accessories
[1] Test Leads: electric rating 1000V 20A
[2] “K” type thermocouple sensor probe
[3] Operator’s Manual