AstroAI CM2K0R Digital Clamp Meter User Manual

Introduction

Thank you for purchasing the AstroAI True RMS 2000 Counts Clamp Meter. This clamp meter has been designed for safe and accurate use by both professionals and DIY enthusiasts. This manual provides all safety information, usage information, specifications, and maintenance information for the clamp meter. This instrument can perform AC/DC voltage tests, resistance tests, audible continuity tests, diode tests, NCV detection, and capacitance tests. Thank you again for choosing AstroAI. If you have any questions or concerns about your product, please contact us at support@astroai.com. Please read and fully understand this manual before use and keep it for future reference.

Warnings

To avoid electric shock or personal injury and possible damage to the instrument or equipment under test, adhere to the following rules:

• Use the clamp meter strictly in accordance with this manual; otherwise, the protection function provided by the clamp meter may be damaged or weakened.
• Pay special attention when measuring values above 60 V DC, 30 V AC RMS, or 42 V peak, as there is a greater risk of electric shock.
• Do not apply a voltage higher than the rated voltage, indicated on the clamp meter, between the terminals or between any terminal and ground.
• Verify if the clamp meter is functioning normally by measuring a known voltage; do not use it if the readings are incorrect or the clamp meter is damaged.
• Before using the clamp meter, check for cracks or damage to the plastic parts of the casing. Do not use the clamp meter if any part of the outer casing is damaged.
• Before using the clamp meter, check if the test leads are cracked or damaged. If the test leads are damaged, please replace them with identical ones of the same model with the same electrical specifications.
• Use the clamp meter according to the measurement category, voltage, or current specified on the clamp meter or in the manual.
• Replace the battery as soon as the low battery indicator ? appears to avoid measurement errors.
• Respect local and national safety regulations. Wear personal protective equipment (e.g., approved rubber gloves, masks, fire-resistant clothing, etc.) to avoid injuries from electric shock and arc flashes when exposed to hazardous live conductors.
• Do not use the clamp meter near explosive gases, vapor, or in humid environments.
• When using the test leads, keep your fingers behind the protective guards.
• Do not measure current when a test lead is inserted into the INPUT terminal.
• Do not leave the meter operating without someone present to monitor it.
• During measurement, connect the neutral or ground wire ⏚ first, then connect the live wire; during disconnection, disconnect the live wire first, then disconnect the neutral and ground wires.
• Remove the clamp meter's test leads before opening the battery cover. Do not use the instrument when it is disassembled or the battery cover is open.
• For safety, the clamp meter can only be used with the supplied test leads. If the test leads are damaged and need to be replaced, replace them only with identical ones of the same model and with the same electrical specifications.

Package Contents

• Owner's Manual x1
• Pair of Test Leads x1
• Storage Bag x1
• AstroAI 2000 Counts CLAMP METER x1

Electrical Symbols

• ~ : AC (Alternating Current)
• --- : DC (Direct Current)
• ~--- : AC and DC
• ☍ : Capacitance
• A : Current
• ⚠️ : Attention
• ⏚ : Ground
• Ω : Resistance
• )))) : Continuity Test
• →| : Diode Test
• ? : Low Battery
• V : Voltage
• ⚡ : Danger of Voltage
• NCV : Non-Contact Voltage Detection

Clamp Diagram

The clamp meter features a NCV detector (1), transformer jaws (2), a torch (3), a data hold button (4), a trigger (5), a rotary switch (6), a FUNC button (7), a torch button (8), a backlight button (9), a MAX/MIN button (10), a display (11), input terminals (12), and a COM terminal (13). The package also includes a storage case (14) and test leads (15).

Dimensions

The clamp meter has dimensions of 19.5 cm in length, 6.8 cm in height, and 2.9 cm in depth.

Button Functions

FUNC ⚙️

Use the rotary switch ? to select a function. Use the FUNC button to select a specific function if multiple functions are present within a setting. Example: switching between AC and DC voltage tests; selecting between diode, resistance, and continuity tests.

NOTE: Pay close attention to the selected setting before performing any test.

HOLD ?️

Press this button during a test to "freeze" the reading for easy recording. The screen will display when the Hold function is active. Press the button again to cancel data hold.

Torch ?

Press this button to turn the torch on/off.

MAX/MIN ?

Press this button to activate the MAX/MIN lock function and press it again to display the maximum and minimum recorded values, respectively. Press and hold the button for more than two seconds to exit this function.

Backlight ?

Press this button to turn the screen backlight on/off.

Input Terminal [input]

Connect the red test lead for all measurements.

COM Terminal [com]

Insert the black test lead into this terminal.

Auto Power Off

If the clamp meter is not in use for 15 minutes, it will automatically turn off. To turn it back on, simply rotate the switch or press any button.

How to Use This Clamp Meter

The clamp meter is very sensitive and will be affected by nearby magnetic fields. Without touching any object, a value may appear on the screen when the instrument is turned on. This is normal for a digital meter and does not affect measurement results.

NOTES:

• To avoid damaging the clamp meter, do not measure voltages above 600 V.
• Pay special attention to safety when measuring high voltages to avoid electric shock or other personal injuries.
• Before using the clamp meter, test it with a known voltage or current to confirm its correct operation.

I. Measuring AC Current

1. Rotate the dial to the "200 / 400 A~" or "2 / 20 A~" setting. The screen will display "AC", indicating that the measurement function is set to AC current.
2. Press the trigger [trigger] to open the clamp jaws, clamp the conductor to be tested, and slowly release the trigger until the clamp jaws are completely closed. Ensure that the conductor to be tested is centered within the clamp jaws. Errors will occur if the conductor is not positioned in the center of the clamp jaws.
3. After the reading stabilizes, record it by reading the LCD screen.
4. Rotate the switch to the OFF position to turn off the instrument.

II. Measuring AC / DC Voltage

1. Insert the red test lead into the input terminal [input] and the black test lead into the COM terminal [com].
2. Rotate the selector to the continuity test ))))). Then, touch the red and black test leads together to ensure they are working. The buzzer will emit an audible signal and the indicator light will turn on if the test leads are functioning normally.
3. Rotate the selector to the "V~" setting. The screen will display "AC", indicating that the measurement function is AC voltage.
4. Rotate the selector to the "V---" setting. The screen will display "V---", indicating that the measurement function is DC voltage.
5. Connect the meter in parallel to the circuit under test.NOTE: If the reading is negative when measuring DC voltage, it means the positive and negative poles of the test leads are reversed. Please swap the test leads.
6. After the reading stabilizes, record the reading from the LCD screen.
7. Rotate the switch to the OFF position to turn off the clamp meter.

Notes on Voltage

• To avoid damaging the clamp meter, do not measure voltages above 600 V DC or 600 V AC CATIII.
• If the AC setting is used to measure DC current, or vice versa, an overflow symbol "OL" will be displayed. This could damage the clamp meter and any components being tested.
• When measuring voltage, the result will fluctuate depending on the power supply. Generally, the result will oscillate by ± 10 V, which is not an inaccurate result.

III. Measuring Resistance

1. Insert the red test lead into the input terminal [input] and the black test lead into the COM terminal [com].
2. Rotate the selector to the continuity test ))))). Then, touch the red and black test leads together to ensure they are working. The buzzer will emit an audible signal and the indicator light will turn on if the test leads are functioning normally.
3. Turn the selector to the "Ω" setting. The screen will display the symbol "Ω", indicating that the measurement function is resistance.
4. Connect the test leads to both ends of the circuit or resistor to be tested (connect the test leads in parallel to the resistance to be tested).
5. After the reading stabilizes, record the reading from the LCD screen.
6. Rotate the switch to the OFF position to turn off the clamp meter.

Notes on Resistance

• Do not change the resistance during measurement. This could damage the clamp meter and affect test results.
• Do not test parallel circuits. Measurement accuracy will be affected, and results may not be accurate.
• Do not directly measure the internal resistance of micrometers, galvanometers, batteries, and similar instruments.

IV. Measuring Capacitance

1. Insert the red test lead into the input terminal [input] and the black test lead into the COM terminal [com].
2. Rotate the selector to the continuity test ))))). Then, touch the red and black test leads together to ensure they are working. The buzzer will emit an audible signal and the indicator light will turn on if the test leads are functioning normally.
3. Rotate the selector to the "ㅓㅏ" setting. Press the FUNC ⚙️ button to switch to capacitance test. The screen will display "nF", indicating that the measurement function is capacitance.
4. Connect the test leads to both ends of the circuit or resistor to be tested (connect the test leads in parallel to the resistance to be tested).
5. After the reading stabilizes, record the reading from the LCD screen.
6. Rotate the switch to the OFF position to turn off the clamp meter.

Capacitance Tips

If the measured value is significantly different from the value indicated on the capacitor, the capacitor is damaged.

Capacitance Notes

• Before measuring the capacitor, discharge it to avoid damaging the multimeter. This can be done by connecting the capacitor to a high-power resistor.
• Discharge the capacitor after measurement to avoid potential safety risks.
• If the capacitance is high, it may take a long time for the reading to stabilize.

V. Continuity Test

1. Insert the red test lead into the input terminal [input] and the black test lead into the COM terminal [com].
2. Rotate the selector to the "))))" setting. The screen will display "))))", indicating that the measurement function is continuity. Then, touch the red and black test leads together to ensure they are working. The buzzer will emit an audible signal if the test leads are functioning normally.
3. Connect the test leads to both ends of the circuit or resistor to be tested (in parallel). If the resistance of the circuit or resistor under test is less than 50 Ω, the buzzer will emit an audible signal, and the measured resistance value will be displayed on the LCD.
4. If the circuit or resistor to be tested is disconnected or the resistance value is greater than 50 Ω, the LCD screen will display "OL".
5. Rotate the switch to the OFF position to turn off the clamp meter.

VI. Diode Test

1. Insert the red test lead into the input terminal [input] and the black test lead into the COM terminal [com].
2. Rotate the selector to the continuity test ))))). Then, touch the red and black test leads together to ensure they are working. The buzzer will emit an audible signal and the indicator light will turn on if the test leads are functioning normally.
3. Rotate the selector to the "→|" setting. Press the FUNC ⚙️ button to switch to diode test. The screen will display "+ ", indicating that the measurement function is diode test.
4. Connect the red test lead to the anode of the diode to be tested and the black test lead to the cathode of the diode.NOTE: Usually, the anode of the diode is the longer lead.
5. The LCD screen will display the approximate forward voltage drop of the diode. If the test leads are connected in reverse, "OL" will be displayed on the LCD screen. Please reverse the test leads to measure again.
6. Rotate the switch to the OFF position to turn off the clamp meter.

Diode Test Tips

• Does the diode function correctly? If the red test lead is connected to the positive pole of the diode and the black test lead to the negative pole, the diode should be in a state of forward conduction, and the displayed value is the forward voltage drop.
• Normal forward voltage drop for diodes: for silicon diodes, generally 0.5-0.7 V; for germanium diodes, 0.15-0.3 V.
• If "0000" is displayed, the diode is broken.
• It is also possible to check if the red test lead is connected to the negative pole of the tested diode and the black test lead to the positive pole. The diode should display "OL".

Method for judging polarity

• Set the clamp meter to the Resistance Ω setting.
• Connect the two test leads to the two electrodes of the diode.
• Measure one result, swap the test lead positions, then measure the second result.
• The larger result represents the reverse resistance, and the smaller result represents the forward resistance. The smaller resistance occurs when the black test lead is connected to the positive end of the diode and the red test lead to the negative end.

VII. Non-Contact Voltage (NCV)

1. Rotate the selector to the "NCV / Live" setting. The screen will display "NCV", indicating that the measurement function is Non-Contact Voltage.
2. Move the NCV detector close to the point to be tested: When the clamp meter detects a weak AC signal, the green indicator light will turn on, the buzzer will emit a slow, audible beep, and the screen will display "---L". When the clamp meter detects a strong AC signal, the red light will turn on, the buzzer will emit a rapid beep, and the screen will display "---H".NOTE: When the indicator light is on, it means there is voltage ⚡. Pay attention to your safety!
3. Rotate the selector to the OFF position to turn off the clamp meter.

VIII. Live Wire Detection

1. Insert the red test lead into the input terminal [input].
2. Rotate the selector to the "NCV / Live" setting. Press the FUNC ⚙️ button to switch to live wire detection. The screen will display "Live", indicating that the measurement function is live wire detection.
3. Touch the point to be measured with the tip of the red test lead: When the indicator light is on, it means the measured point is a live wire ⚡. Pay attention to your safety! A green light may indicate that the test lead is not fully connected to the socket. Perform the test again after confirming the test lead is correctly connected.NOTE: When the instrument detects a weak AC signal, the LCD screen will display "---L" and the buzzer will emit a slow beep. When the instrument detects a strong AC signal, the LCD screen will display "---H" and the buzzer will emit a short beep.
4. Rotate the selector to the OFF position to turn off the clamp meter.

MAINTENANCE

Cleaning the Clamp Meter

If there is dust or moisture in the terminals, incorrect measurements may occur. Please clean the clamp meter as described:

• Turn off the power to the Meter and remove the test leads. Interrupt the power supply to the clamp meter and remove the test leads.
• Turn the instrument upside down and shake off accumulated dust from the input terminal. Then, clean the clamp meter body with a damp cloth or a neutral detergent. Clean the contacts in each terminal with a cotton swab moistened with alcohol.

BATTERY REPLACEMENT

If the low battery indicator ? appears on the LCD display, the battery must be replaced immediately. Remove the screws and open the rear casing, replace the depleted batteries with new batteries (2 AAA type, 1.5 V).

NOTE: Replace batteries immediately to avoid inaccurate readings caused by low power. This can also prevent potential safety risks.

SPECIFICATIONS

DETAILED SPECIFICATIONS

I. Precision Index

• Ambient Temperature: 18 °C to 28 °C
• Relative Humidity: ≤ 80%
• Accuracy: ± (%rdg + dgts)
• The accuracy is constant within one year of calibration.

II. DC Voltage

Input Impedance: 10 MΩ

Overload Protection: 600 V

Maximum Measurement Voltage: 600 V

III. AC Voltage

Input Impedance: 10 MΩ

Overload Protection: 600 V

Maximum Measurement Voltage: 600 V

Frequency Range: 40 Hz ~ 1k Hz

Response: True RMS

IV. AC Current

Frequency Range: 40Hz ~ 400Hz

Response: True RMS

V. Resistance

Overload Protection: 250 V

VI. Capacitance

VII. Continuity Test

The buzzer )))) inside the clamp meter emits an audible signal if the resistance is <50 Ω.

Open circuit voltage: approx. 1.0 V

Overload Protection: 250 V

VIII. Diode Test

The approximate forward voltage drop of the diode →| will be displayed.

Reverse DC voltage: approx. 2.0 V

Overload Protection: 250 V

HOW TO DISPOSE OF THE CLAMP

If you intend to dispose of this product, please note that many of its components are made of valuable materials that can be recycled. Please do not throw it in the trash. Check with local authorities for the most appropriate waste recycling facilities in your area.

WARRANTY PERIOD

3-year limited warranty from AstroAI.

Every AstroAI digital meter is free from defects in material and workmanship.

This warranty does not cover fuses, disposable batteries, and damage resulting from negligence, improper use, contamination, alteration, accidents, or abnormal operating conditions or handling, including surge failures caused by use outside the specified power of the clamp meter or normal wear and tear of mechanical components. This warranty covers the original purchaser only and is non-transferable.

If this product is defective, please contact AstroAI Customer Support at support@astroai.com.

Contact Information

Web: www.astroai.com

E-mail: support@astroai.com