HTC CM-2070FT User manual

CM‐2070FTDigitalClampMeterManual
CONTENTS
SUMMARY………………………………1
SAFETY NOTICE………………………………1
FEATURES………………………………1
GENERAL FEATURES…………………………1
TECHNICAL FEATURES…………………………1
OPERATION…………………………1
PANEL DESCRIPTION…………………………1
ACA MEASUREMENT…………………1
ACV MEASUREMENT…………………1
DCV MEASUREMENT…………………1
NCV MEASUREMENT…………………1
DIODE AND CONTINUITY TEST……………1
RESISTANCE MEASUREMENT………………………1
CAPACITANCE MEASUREMENT………………………1
FREQUENCY MEASUREMENT………………………1
TEMPERATURE TEST………………………1
AUTO POWER OFF………………………1
MAINTENANCE…………………………1
TROUBLE SHOOTING…………………………1
1. SUMMARY
This 3 3/4 Digit Highly Stable clamp meter uses two AAA (1.5V)
batteries. It has a LCD with 18mm digit display, which makes the
reading clearer and the operation more convenient. It can test DCV,
ACV, ACA, resistance, NCV, temperature, diode, and continuity test.
This meter also equips data hold function with unit symbol display,
can work in both auto and manual range, and provides auto power off,
clamp light, backlight and warning functions. To assure high
accuracy and resolution, it adopts an 8-bit microprocessor and a dual
integral A/D convertor IC .It is an ideal tool for labs, factories
radio-technology and household.
2. SAFETY NOTICE
The instrument is designed according to IEC1010-1 standard (safety
standard issued by International Electro technical Committee), CAT
III600V and UL3111-1. Please read the followings carefully before
any operation.
2.1 Please disconnect any signal and pluck out the test leads before
opening the outside cover.
2.2 To avoid electric shock and damage to the meter, water should not
be leaked inside.
2.3 DO NOT use this meter to do any test if the case hasn’t
finished installation and its screws haven’t been tightened.
2.4 DO NOT input the value higher than the limit at every
range.
2.5 Please don’t input voltage in resistance terminal.
2.6 Please turn the power switch to OFF after the test.
2.7 To avoid the damage of battery leakage to the meter, please
remove the battery for long-term storage.
2.8 To avoid electric shock and damage to the meter, do not
input voltage higher than DC 60V or AC 30V during the
measurement.
2.9 To avoid electric shock, please be seriously careful when
nipping the bus bar or something insulated.
2.10 Introduction for safety symbols:
: Existing High Voltage.
: Dual Insulation.
: Operator must refer to manual.
: Low battery indication.
3. FEATURES
3.1 GENERAL FEATURES
3.1.1 Display: LCD.
3.1.2 Max. display: 4000 digits (3 3/4) , and auto polarity display .
3.1.3Clamp open: Max. Open: 52mm.
3.1.4 Over-range display: “OL” displayed.
3.1.5 Data hold.
3.1.6 Relative Value measurement.
3.1.7 Sampling rate: approx.3 times/sec.
3.1.8 Low battery indicator: “ ”displayed.
3.1.9 Continuity test: buzzer sounds when<（50±10）Ω.
3.1.10 Range: Auto range or Manual range.
3.1.11 Auto power off.
3.1.12 Power consumption: about 3mA.
3.1.13 Power: 2 X 1.5V batteries (AAA).
3.1.14Working environment: (0～40)℃, relative humidity: <70%.
3.1.15Dimension: 123mm×270mm×35mm (width×length×height).
3.1.16 Weight: approx. 280g (including battery).
3.1.17 Accessories: user manual, certificate, test leads, temperature
sensor TP01 banana probe, two AAA batteries.
3.2 TECHNICAL FEATURES
3.2.1 Accuracy:± (a% × reading data + digits). To assure accuracy, the
environment temperature should be (23±5) ℃, relative humidity be
<70%.
One year accuracy guarantee since production date.
3.2.2 Temperature coefficient: 0.1×specified accuracy/1℃（＜18℃or
＞28℃）.
3.2.3 DC voltage (DCV)
Range Accuracy Resolution
400mV ±(1.0% reading+5）0.1mV
4V
±(0.5% reading+5）
1mV
40V 10mV
400V 100mV
1000V 1V

Input impedance: 10MΩ.
Overload protection: 1000V TRMS.
3.2.4 AC voltage (ACV)
Range Accuracy Resolution
400mV ±(1.5% reading+5）0.1mV
4V
±(1.0% reading+5）
1mV
40V 10mV
400V 100mV
750V 1V
Input impedance: 10MΩ.
Overload protection: 1000V TRMS.
Frequency response: at 750V range: 50Hz-60Hz, at other ranges:
40Hz-400Hz.
3.2.5 AC current (ACA)
Range Accuracy Resolution
400A ±(2.0% reading+5）
>800A:(4.0%
reading+10）
100mA
1000A 1A
Overload protection: >600A, input time<1 minute.
Frequency response: 50Hz-60Hz.
3.2.6 Resistance
Range Accuracy Resolution
400Ω±(0.8% reading+5）0.1Ω
4kΩ
±(0.8% reading+3）
1Ω
40kΩ10Ω
400kΩ100Ω
4MΩ1kΩ
40MΩ±(1.2% reading+5）10kΩ
Overload protection: 250V TRMS.
Warning: DO NOT input voltage value at this range!
3.2.7 Capacitance
Range Accuracy Resolution
4nF ±(5.0% reading+20）1pF
40nF
±(3.5% reading+10）
10pF
400nF 100pF
4uF 1nF
40uF 10nF
200uF ±(5.0% reading+10）100nF
Overload protection: 250V TRMS.
Warning: DO NOT input voltage value at this range!
3.2.8 Frequency
Range Accuracy Resolution
100Hz
±(0.5% reading+5）
0.1Hz
1kHz 0.1Hz
10kHz 1Hz
100kHz 10Hz
1MHz 100Hz
10MHz 1kHz
Input sensitivity: >0.7V.
Overload protection: 250V TRMS.
3.2.9 Temperature
Range Accuracy Resolution
（-40～750）℃
＜400℃±（1.0%+5）
≥400℃±（1.5%+15）
1℃
Sensor: K type banana plug (Nickel-chromium-Nickel silicon).
Warning: DO NOT input voltage value at this range!
3.2.10 Continuity Test
Range Description Test Conditions
Diode forward
voltage drop
Forward DC
current is approx
0.5mA, reverse
voltage is
approx 1.5V.
When the resistance
under test is less
than 50±10Ω,
buzzer sounds
continuously.
Open circuit
voltage: 0.5V
Overload protection: 250V TRMS.
Warning: DO NOT input voltage value at this range!
4. OPERATION
4.1PANELDESCRIPTION
(refer to picture 1)
1) ①Jaw: 0 to 1000 AC current and NCV
detecting device.
2) ②Hand protection: A safe design to protect
users from touching the dangerous area.
3) ③Clamp gunlock: Pressing the gunlock can turn on or off the
clamp.
4) ④Clamp light：Opening the clamp light can light up the tested area
in the dark to prevent the danger.
5) ⑤NCV indicator: Detect the existence of the high voltage around to
prevent the electric shock.
6) ⑥Hold button: When pressing this button, the current measured
value will be kept on the LCD and cannot measure any new value at the
moment. Press this Hold button again to exit the hold mode.
7) ⑦Function choosing switch: Used to select the function, range or
turn on or turn off the clamp meter.

Function Description
ACA measurement.
ACV、DCV measurement.
NCV Non-contact voltage test.
Ω
Press “SELECT” to turn to Diode 、
Continuity 、Capacitance and Resistance
measurement.
Hz
Frequency measurement. Press “Hz/DUTY” to
turn to Frequency/Duty measurement.
/℃℉
Temperature measurement. Press” SELECT” to
turn to or .℃℉
8) Function key.
LIGHT button: Backlight and Clamp light control key. Press
LIGHT button more than 2 seconds, backlight and clamp light will be
on. Press this button again, the backlight and clamp light will be off.
The backlight will auto turn off after 5 seconds if not pressing it again.
RANGE button: Auto or manual range control key. The meter defaults
to auto range in measurement function and “AUTO” symbol is
displayed. To enter Manual Range mode, press RANGE key. Each press
of RANGE key increases the range. When the highest range is reached,
the meter wraps to the lowest range. To exit the manual range mode,
press and hold the Range key for more than 2 second.
SELECT button: (1) Function selection key. Press this button to select
the measurement mode: Under “ ” mode, choose DC or AC. Under
“Ω” mode, choose “ ”, “ ”, “ ”，“Ω” measurement.
(2) Hz/DUTY button: When measuring AC voltage / AC current, press
this key can turn to Frequency/Duty/Voltage (Current) measurement.
When measuring Frequency, press this key can turn to Frequency/ Duty
(1-99%) measurement.
(3) REL button: Press this key can clear the reading and enter the
Relative Value measurement. “REL” will be displayed on the LCD,
Press this key again can exit Relative Value measurement mode.
9) LCD: Displaying measurement value and unit.
No. S
y
mbol Descri
p
tion
1-Indicatesne
g
ative readin
g
s.
2 AC AC measurement.
3 DC DC measurement.
4 Auto Auto ran
g
e.
5Null.
6Diode test.
7Continuit
y
bee
p
er is on.
8 HOLD Data hold.
9 REL Relative Value
10 Low batter
y
indication.
11
hFE
℃, ℉
NCV
nF, uF
MΩ, kΩ, Ω
mV, V
uA, mA, A
Hz，kHz，MHz
Null.
℃. ℉is null.
Non-contact voltage test.
nF, uF
MΩ, kΩ, Ω.
mV, V.
uA, mA, A.
Hz，kHz，MHz
10）V/Ωinput terminal: Measurement inputs positive terminal (red
test lead).
COM input terminal: Measurement inputs negative terminal (black
test lead).
11) Carrying belt.
4.2 ACA MEASUREMENT
(1) Turn the rotary switch to ACA range.
(2) Open the clamp jaw and grip one wire and
get the reading directly.
To get the most precise reading, should user
put the wire in the middle of the close jaw
(refertothepicture3).
Note:
1. Firstly users should select the highest range, if users are
not sure about the range of current under test, and then select the
proper range based on displaying value.
2. DO NOT input the current higher than the limit, or it would
damage the meter.
4.3 ACV MEASUREMENT
(1) Turn the function swift to ACV range.
Insert the black test lead into “COM” terminal,
and the red one into “V/Ω” terminal.
(2) Connect the test leads into the circuit and
get the measurement value from the LCD. (refer
to picture 4)
Note: (picture4)
1. DO NOT input a voltage over the limit or It may cause damage
to the circuit of the meter.
2. Be careful while measuring a high voltage circuit. Do not touch
the high voltage circuit.
4.4 DCV MEASUREMENT
(1) Turn the function swift to DCV range. Insert the black test lead
into “COM” terminal, and the red one into “V/Ω” terminal.
(2) Connect test leads to the test point. LCD will display polarity
and voltage of the test point connected by the red test lead.
Note:
1. DO NOT input a voltage over the limit or It may cause damage
to the circuit of the meter.
2. Be careful while measuring a high voltage circuit. Do not touch
the high voltage circuit.
4.5 NCV MEASUREMENT
NCV Static electricity or other sources of energy may randomly
trigger the sensor. The result is only for reference.
4.5.1 Turn the rotary switch to NCV position.
4.5.2 Hold the top of the meter very close to the
voltage source under test.
4.5.3 If voltage is present, the NCV LED will
glow and buzzer will beep.
NOTE:
1. Even no indication when NCV test, there might still voltage be.
Do not use this NCV test function to judge the existence of
voltage.
2. The test result might be affected by many factors such as the
design of the socket and the thickness of insulation material.
3. The LED light might glow when user inputs voltage into the
meter terminal.
4. Flashlight or motor driver and other external sources may cause

disturbance and might cause the wrong results.
4.6 DIODE AND CONTINUITY TEST
4.6.1 Set the rotary switch to “ Ω” range. The
original state is diode measurement mode. (Refer to
picture 6)
4.6.2 Forward measurement: Connect red test lead to
the positive polarity and the black test lead to the
cathode polarity of the diode. LCD will display the
approx. value of forward voltage drop. (picture 6)
4.6.3 Backward measurement: connect red test lead to the cathode
polarity and the black test lead to positive polarity of the diode. LCD
will display “OL”.
4.6.4 The complete diode testing includes forward and backward
measurement. If the result doesn’t meet the descriptions above, it means
the diode is broken.
4.6.5 Press SELECT (yellow) key to select the continuity measurement
mode.
4.6.6 Insert the black test lead into “COM” terminal, and the red one
into “V/Ω” terminal.
4.6.7 Connect test leads to two points of tested circuit, if the resistance
is less than (50±10) Ω, the buzzer sounds.
Note: DO NOT input any voltage value at this range!
4.7 RESISTANCE MEASUREMENT
4.7.1 Turn the function swift to “ Ω” range. Press “SELECT”
to turn to “Ω” measurement mode.
4.7.2 Insert the black lest lead into “COM” terminal and the red one
into “V/Ω” terminal.
4.7.3 Connect the test leads to the measured resistance to get the
measurement value. (Refer to picture 6)
Note:
1. Before measuring in line resistor, make sure that the power is off and
all capacitors have discharged completely.
2. Do not apply any voltage at resistance range.
3. When input terminal is in open circuit, LCD will display “OL”.
4. When the test leads are shorted, there would be about 1Ωstray
resistance.
4.8 CAPACITANCE MEASUREMENT
4.8.1 Turn the function swift to “ Ω” range. Press “SELECT”
to turn to “ ” measurement mode.
4.8.2 Insert the black lest lead in “COM” terminal and the red one in
“V/Ω” terminal.
4.8.3 If the LCD doesn’t display “0”, press “REL” to clear the reading;
4.8.4 Connect the capacitor to “COM” and “V/Ω” terminal. (Note: the
red test leads is for positive pole +). LCD displays capacitance value.
Note:
1. Don’t input voltage or current to the “V/Ω/” terminal when
measuring the capacitance or the capacitor still in the “Cx” terminal.
2. In order to assure the accuracy, please press “REL” to clear the
reading before testing.
3. There is only the auto range mode under the capacitance range.
4. The capacitor must be completely discharged before testing.
5. The reading of 200uF range will take more than 15 seconds to be
stable.
4.9 FREQUENCY MEASUREMENT
4.9.1 Turn the function swift to Hz range. Insert the black lest lead in
“COM” terminal and the red one in “V/Ω” terminal.
4.9.2 Connect the test leads to the measured circuit
and get the measurement value. (Refer to picture 7)
Note:
1. In noisy environment, it's better to use shield
cable to measure a low signal.
2. When measuring high voltage circuit, do not touch the high voltage
circuit;
3. Don’t input voltage higher than 250V TRMS or it may damage the
meter.
4.10 TEMPERATURE TEST
4.1.11 Set the rotary switch to “℃/℉” range.
4.1.12 Insert the black plug of the thermocouple
sensor into “COM” and red one into “V/Ω” jack,
and put the working terminal (temperature
measuring end) of thermocouple on the surface or
inside the object to be tested. Then you can read
temperature from the screen, and the data is in
Centigrade. (Refer to picture 8)
Note:
1. The meter should be far away high temperature. Use the
thermocouple probe within the specified temperature range.
2. Don’t change the temperature probe randomly, or the accuracy will
not be guaranteed.
3. Don’t input voltage at temperature range.
4.11 AUTO POWER OFF
4.11.1 The meter will auto power off if there is not any operation in 15
minutes and come into dormant mode. The beeper will sound five times
within 1 minute before power-off.
To restart the meter, please press any function key or turn to the
function swift.
4.11.2 Press “SELECT” key and turn on the meter or press “SELECT”
when the meter is in dormant mode to wake up the meter and the
“AUTO POWER OFF” function will be cancelled
5. MAINTENANCE
The meter is a precise instrument. Random changes to the circuit should
be avoided.
Note:
1. When the LCD displays “ ”, please exchange the battery in time.
2. Before replacing battery or fuse, please remove the test leads from
the measuring point and turn off the power.
3. Keep the meter away from water, dust and shock.
4. DO NOT use the meter under high temperature, high humidity,
combustible, explosive and strong magnetic environments.
5. Clean the case of the meter regularly with cleaner. DO NOT use
corrosive solvents.
6. TROUBLE SHOOTING
If the meter does not work properly, please check the meter as
following steps:
(If the problems still cannot be solved, please refer to repairing center
or contact the local dealers.)
Fault Solution
No reading on LCD
Turn on the power
Replace battery
Release the HOLD key
signal appears Replace battery
No current or temperature input Replace fuse
Big error Value Replace battery


■ The specifications are subject to changes without prior notice.
■ The content of this manual is regarded as correct. If users find out
any mistakes or omissions, please kindly contact the manufacturer.
■ The manufacturer will not be responsible for accidents and damage
caused by improper operations.
■ The functions described in this User Manual shall not be
considered as the reason for any special usages.
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