Input Terminals
LCD Display
Functional Buttons
Rotary Switch
Transformer Jaws
Trigger
Figure 1
1
OPERATING INSTRUCTIONS
Digital Clamp Meter
Model GCM-221
Read this owners manual thoroughly before use and save.
International Electrical Symbols
AC (Alternating Current)
DC (Direct Current)
Grounding
Double Insulated
Warning. Refer to the Operating Manual
Low Battery Indication
Continuity Test
Diode
Conforms to Standards of European Union
Number
Description
1 Indicator for AC voltage or current
2 Indicator for DC voltage
3 The battery is low.
Warning: To avoid false readings, which
could lead to possible electric shock or
personal injury, replace the battery as soon as
the battery indicator appears.
4 The Meter is in the auto range mode in
which the Meter automatically selects
the range with the best resolution.
5 Test of diode
6 The continuity buzzer is on
7 Maximum reading displayed
8 Data hold is active
9 Amperes (amps). The unit of current.
10 Ω: Ohm. The unit of resistance.
kΩ:Kilohm. 1000 ohms
MΩ:Megohm. 1,000,000 ohms
11 V: Volts. The unit of voltage.
mV: Millivolt. 0.001 volts
12 Indicates negative reading
Rotary Functional Buttons
Switch
SELECT MAX HOLD
Positions
Ω •
N/A
•
N/A •
•
N/A •
•
A 20A N/A •
•
A 200A N/A •
•
A 600A N/A • •
A. AC Voltage: Auto Ranging
Range Resolution
Accuracy
2.000V 1mV
20.00V 10mV ±(1.2%+5)
200.0V 100mV
600V
1V
±(1.5%+5)
B. DC Voltage: Auto Ranging
Range Resolution
Accuracy
200.0mV 0.1mV ±(0.8%+3)
2.000V 1mV
20.00V 10mV ±(0.8%+1)
200.0V 100mV
600V
1V
±(1%+3)
Remarks:
● Input impedance: 10MΩ
● Overload protection: 600V rms
C. Resistance: Auto Ranging
Range Resolution
Accuracy
200.0Ω 100mΩ
±(1.2%+2)
2.000kΩ 1Ω
20.00kΩ 10Ω
±(1%+2)
200.0kΩ 100Ω
2.000MΩ 1kΩ ±(1.2%+2)
20.00MΩ 10kΩ ±(1.5%+2)
Remark:
● Overload protection: 600Vp
D. Continuity
Range Resolution Accuracy
Around <10Ω,the
buzzer beeps.
Remark:
● Overload Protection: 600Vp
● Open circuit voltage approximate 0.45V.
● The buzzer may or may not beeps when the
resistance of a circuit under test is more
than 10Ω.
E. Diode
Range Resolution
Accuracy
Display approximate
forward voltage drop
Remarks:
● Overload Protection: 600Vp
● Open circuit voltage approximate 1.48V.
1mV
100mΩ
F. AC Current: Auto Ranging
Range Resolution Accuracy
20.00A 0.01A ±(2.0%+5)
200.0A 0.1A
±(1.5%+5)
600A
1A ±(2.0%+8)
Remarks:
International Electrical Symbols
AC (Alternating Current)
DC (Direct Current)
Grounding
Double Insulated
Warning. Refer to the Operating Manual
Low Battery Indication
Continuity Test
Diode
Conforms to Standards of European Union
Number
Description
1 Indicator for AC voltage or current
2 Indicator for DC voltage
3 The battery is low.
Warning: To avoid false readings, which
could lead to possible electric shock or
personal injury, replace the battery as soon as
the battery indicator appears.
4 The Meter is in the auto range mode in
which the Meter automatically selects
the range with the best resolution.
5 Test of diode
6 The continuity buzzer is on
7 Maximum reading displayed
8 Data hold is active
9 Amperes (amps). The unit of current.
10 Ω: Ohm. The unit of resistance.
kΩ:Kilohm. 1000 ohms
MΩ:Megohm. 1,000,000 ohms
11 V: Volts. The unit of voltage.
mV: Millivolt. 0.001 volts
12 Indicates negative reading
Rotary Functional Buttons
Switch
SELECT MAX HOLD
Positions
Ω •
N/A
•
N/A •
•
N/A •
•
A 20A N/A •
•
A 200A N/A •
•
A 600A N/A • •
A. AC Voltage: Auto Ranging
Range Resolution
Accuracy
2.000V 1mV
20.00V 10mV ±(1.2%+5)
200.0V 100mV
600V
1V
±(1.5%+5)
B. DC Voltage: Auto Ranging
Range Resolution
Accuracy
200.0mV 0.1mV ±(0.8%+3)
2.000V 1mV
20.00V 10mV ±(0.8%+1)
200.0V 100mV
600V
1V
±(1%+3)
Remarks:
● Input impedance: 10MΩ
● Overload protection: 600V rms
C. Resistance: Auto Ranging
Range Resolution
Accuracy
200.0Ω 100mΩ
±(1.2%+2)
2.000kΩ 1Ω
20.00kΩ 10Ω
±(1%+2)
200.0kΩ 100Ω
2.000MΩ 1kΩ ±(1.2%+2)
20.00MΩ 10kΩ ±(1.5%+2)
Remark:
● Overload protection: 600Vp
D. Continuity
Range Resolution Accuracy
Around <10Ω,the
buzzer beeps.
Remark:
● Overload Protection: 600Vp
● Open circuit voltage approximate 0.45V.
● The buzzer may or may not beeps when the
resistance of a circuit under test is more
than 10Ω.
E. Diode
Range Resolution
Accuracy
Display approximate
forward voltage drop
Remarks:
● Overload Protection: 600Vp
● Open circuit voltage approximate 1.48V.
1mV
100mΩ
F. AC Current: Auto Ranging
Range Resolution Accuracy
20.00A 0.01A ±(2.0%+5)
200.0A 0.1A
±(1.5%+5)
600A
1A ±(2.0%+8)
Remarks:
I. DISPLAY SYMBOLS
DC
AC
AUTO
T
RMS
MAX
˚C˚F
A
A
A
VA
MK
Ω
m
3
9
10
2
12
1
11
4
5 6
7
8
Figure 2
