770HC
DIGITAL MULTIMETER
OPERATOR’S MANUAL
1. Overview
The multimeter is characterized at slim size, portable, stable performance and anti-dropping capacity.
Using 6000 counts digit LCD monitor with character 25mm 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 ( 600A range with AC/DC
current clamp adapter), resistance, capacitor, frequency, duty cycle, temperature, transistor hFE, Non
Contact AC Voltage (NCV) detection, positive diode voltage fall and audible continuity.
2. Panel Layout
①
NCV detection area: Non Contact AC Voltage (NCV) detection area.
②
CDS
sensor:
The CDS sensor can reaction to the ambient brightness range, then automatically
control the LCD backlight to lighten or go out.
③
NCV red light: Non Contact AC Voltage (NCV) detection red light.
④
NCV green light: Non Contact AC Voltage (NCV) detection green light.
⑤
LCD display: 6000 counts digit, full function symbol display.
⑥
SELECT
key: This key work on the "
" range, press the key to choose resistance
、
diode
、
continuity or capacitance 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.
⑦
RANGE
Key: Press the “
RANGE
” key, the meter enters manual range mode, press it more than
2 seconds again, return to auto mode.
⑧
REL
▲
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 R
EL
△
=measurement value-Reference value
. Press it again
to exit.
⑨
Hz/Duty
Key: On “ACV/ACA” or “Hz” range, press the “
Hz/Duty
” key, you can choose the
Frequency
or
Duty Cycle
measurement.
⑩
HOLD
key: Press the “
HOLD
” key to lock display value, and the “
DH
” sign will appear on the
display, press it again to exit.
⑪
MAX/MIN
key: Press the “
MAX/MIN
” key to lock
MAX
,
MIN
or
MAX-MIN
value, and the “
MAX
”,
“
MIN
” or “
MAX-MIN
” sign will appear on the display, press it over 2 seconds to exit.
⑫
Rotary Switch: Use this switch to select functions and ranges.
⑬
μA:
μAmA, 600A current clamp adapter and Temperature “+” Input Jack
⑭
20A:
20A Input Jack
⑮
VΩHz
:
V/Hz/
Input Jack
⑯
COMT-:
COM and Temperature “-” Input Jack
⑰
Transistor hFE test Input Jack
⑱
Crust of meter
⑲
Protective 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
Ⅲ
1000V
5-2 Over-range Indication: display “OL” for the significant digit.
5-3 Automatic display of negative polarity “-” .
5-4 Low Battery Indication: “
” displayed.
5-5 Max LCD display: 6000 counts digit.
5-6 Auto range & Manual range control
5-7 Auto 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: 800mA/500V Fast Fuse, 20A/500V Fast Fuse
5-10 Power supply:
9
V
6F22
battery
5-11 Operating Temp.: 0
℃
to 40
℃
(relative humidity <85%)
5-12 Storage Temp.: -10
℃
to 50
℃
(relative humidity <85%)
5-13 Guaranteed precision Temp.: 23±5
℃
(relative humidity <70%)
5-14 Dimension: 195x88x40mm
5-15 Weight: approx. 350g (including battery)
6. Testing Specifications
Accuracy is specified for a period of year after calibration and at 18
℃
to 28
℃
(64
℉
to 82
℉
) with relative humidity to 70%.
6-1 DC Voltage
Range
Resolution
Accuracy
60mV
0.01mV
±(0.8% of rdg + 2 digits)
600mV
0.1mV
±(0.5% of rdg + 2 digits)
6V
1mV
60V
10mV
600V
100mV
1000V
1V
±(0.8% of rdg + 2 digits)
-- Impedance: 10MΩ, More than 100MΩ on 60mV/600mV range
-- Overload protection: 1000V DC or 750V AC rms
6-2 AC Voltage (True RMS)
Range
Resolution
Accuracy
60mV
0.01mV
±(1.5% of rdg + 3 digits)
600mV
0.1mV
±(1.0% of rdg + 3 digits)
6V
1mV
60V
10mV
600V
100mV
750V
1V
±(1.5% of rdg + 3 digits)
-- Impedance: 10MΩ, More than 100MΩ on 60mV/600mV range
-- Overload protection: 1000V DC or 750V AC rms
-- Frequency Range: 40 to 400Hz
6-3 DC Current
Range
Resolution
Accuracy
600μA
0.1μA
±(1.2% of rdg + 2 digits)
6000μA
1μA
60mA
10μA
600mA
100μA
6A
1mA
±(2.0% of rdg + 3 digits)
20A
10mA
600A
100mA
±(2.5% of rdg + 5 digits)
-- 600A range with AC/DC Current Clamp Adapter
-- Overload protection: 800mA/500V Fast Fuse, 20A/500V Fast Fuse, 20A up to 10 seconds
6-4 AC Current (True RMS)
Range
Resolution
Accuracy
600μA
0.1μA
±(1.5% of rdg + 3 digits)
6000μA
1μA
60mA
10μA
600mA
100μA
6A
1mA
±(2.5% of rdg + 5 digits)
20A
10mA
600A
100mA
±(3.0% of rdg + 5 digits)
-- 600A range with AC/DC Current Clamp Adapter
-- Overload protection: 800mA/500V Fast Fuse, 20A/500V Fast Fuse, 20A up to 10 seconds
-- Frequency Range: 40 to 400Hz
6-5 Resistance
Range
Resolution
Accuracy
600Ω
0.1Ω
±(1.0% of rdg + 3 digits)
6kΩ
1Ω
±(1.0% of rdg + 2 digits)
60kΩ
10Ω
600kΩ
100Ω
6MΩ
1kΩ
60MΩ
10kΩ
±(1.5% of rdg + 3 digits)
-- Overload protection: 500V DC or AC rms
6-6 Capacitance
Range
Accuracy
Resolution
9.999nF
±(3.0% of rdg + 10 digits)
1pF
99.99nF
±(2.5% of rdg + 5 digits)
10pF
999.9nF
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)
-- Overload protection: 500V DC or AC rms
6-8 Duty cycle
