AstroAI M4KOR True RMS Digital Multimeter

Introduction

Thank you for choosing the AstroAI True RMS 4000 Counts Digital Multimeter. This battery-powered multimeter features a 4000-count display and automatic range selection. It is designed to measure AC/DC current, AC/DC voltage, resistance, capacitance, and perform non-contact voltage (NCV) detection, diode tests, continuity tests, and battery voltage tests.

If you have any questions or concerns regarding your product, please contact AstroAI support at support@astroai.com.

Safety Precautions

Please adhere to the following rules to avoid electric shock, injury, and damage to the multimeter or the devices being tested:

• Inspect the outer casing before using the multimeter. Do not use it if it is damaged or parts of the casing are missing. Check for cracks and missing plastic parts, paying special attention to the insulation on the connectors.
• Do not use or store the multimeter in high ambient temperatures or expose it to high humidity or strong magnetic fields, as this may affect performance.
• Inspect the test leads for damaged insulation or exposed metal parts. Check the test leads for continuity.
• Be particularly careful when selecting settings for measuring current and voltage. Incorrect settings can damage the multimeter.
• Do not apply more than the rated voltage indicated on the multimeter between the terminals or between a terminal and ground.
• Exercise caution when applying voltage greater than 60 V DC or 30 V AC RMS, as there is an increased risk of electric shock.
• Use the correct jacks, functions, and ranges for your measurements.
• Keep your fingers behind the finger guard when handling the test leads.
• Disconnect the circuit from the power source and discharge all high-voltage capacitors before performing resistance, continuity, or diode tests.
• Disconnect the test leads from the circuit being tested. Turn off the multimeter before opening its casing.
• Use only replacement parts with the same model number or identical electrical specifications for maintenance.
• Do not alter the internal circuitry of the multimeter to avoid damage.
• Use a soft cloth and mild detergent to clean the multimeter's surface. Do not use abrasive cleaners or solvents, as they can corrode and damage the surface.
• Turn off the multimeter when not in use. Remove the battery if the multimeter will not be used for an extended period. Inspect the battery regularly, as it may leak if left unused for a long time.
• Replace the battery immediately if it begins to leak, as a leaking battery can damage the multimeter.
• Avoid moving the multimeter during measurements, as this can lead to inaccurate readings.

Scope of Delivery

• User Manual x 1
• AstroAI 4000 Counts Multimeter x 1
• Pair of Test Leads x 1

Electrical Symbols

• ⚠️: Caution
• ⚡: AC and DC
• ?️: Fuse
• ?: Ground
• ⬇️: DC (Direct Current)
• 〰️: AC (Alternating Current)
• ⛑️: Double Insulation
• ?❗: Low Battery Indicator
• ✅: CE Compliant (Meets EU Standards)

CAT III test equipment is suitable for testing and measuring circuits connected to the distribution level of a low-voltage supply in a building.

Dimensions

The multimeter measures approximately 5.9 inches (150 mm) in length and 2.8 inches (71 mm) in width.

Device Overview

The AstroAI M4KOR multimeter features a clear LCD display, a rotary switch for function selection, and several buttons for specific operations.

Key Components:

• NCV Detector: Located at the top, used for non-contact voltage detection.
• Status LED: Indicates measurement status (e.g., continuity, NCV signal strength).
• Hold Button: Freezes the current measurement on the display.
• FUNC Button: Selects specific functions or modes within a rotary switch setting.
• Rotary Switch: Selects the primary measurement function (e.g., Voltage, Resistance, Current).
• COM Jack: Common input jack for test leads (usually black).
• 10A Jack: Input jack for high current measurements (up to 10A).
• Flashlight: Built-in LED light for illuminating the measurement area.
• LCD Display: Shows measurement readings, units, and status indicators.
• MAX Button: Displays and freezes the maximum value recorded during a measurement.
• Backlight / Flashlight Button: Toggles the LCD backlight and the flashlight on/off.
• Input Jack: Primary input jack for test leads (usually red), used for most measurements except high current.
• Test Leads: Used to connect the multimeter to the circuit or component being tested.

Button Functions:

• Hold Button: Press this button during a measurement to freeze the reading. An "H" will appear on the display.
• FUNC Button: Use this button to select a specific function when the rotary switch offers multiple options for a single setting.
• MAX Button: Press this button to display and freeze the maximum value captured by the multimeter during a measurement.
• Backlight / Flashlight Button: Press to turn the LCD backlight on/off. Press to turn the flashlight on/off.

Rotary Switch Functions:

• V= (DC Voltage): Measures DC voltage from 0.01 V to 600 V.
• mV≈ (AC/DC Millivoltage): Measures AC/DC millivoltage from 0.1 mV to 400 mV.
• Ω (Resistance): Measures resistance from 0.1 Ω to 40 MΩ.
• Capacitance (NF/MF): Measures capacitance from 0.01 nF to 4 MF.
• Continuity ())) : Checks for continuity in a circuit; beeps if continuity is present.
• Diode Test (➡️+): Tests diodes by measuring forward voltage drop.
• Battery Test (1.5V, 9V, 12V): Tests common battery voltages.
• mA≈ (AC/DC Milliamperage): Measures AC/DC current from 0.01 mA to 400 mA.
• A≈ (AC/DC Amperage): Measures AC/DC current from 400 mA to 10 A.
• NCV/Live: Non-Contact Voltage detection and Live wire detection.
• OFF: Turns the multimeter off.

Input Jacks:

• 10A Jack: For current measurements between 400 mA and 10 A.
• COM Jack: Common terminal for test leads (black).
• mA Jack: For current measurements less than 400 mA.

Operating Instructions

Voltage Measurement

1. Insert the red test lead into the Input jack (red) and the black test lead into the COM jack (black).
2. Turn the rotary switch to the "V≈" setting for AC/DC voltage measurement. If the voltage is expected to be less than 400 mV, turn the switch to the "mV≈" setting. Use the FUNC button to switch between AC and DC if applicable.
3. Connect the test leads to the circuit: red lead to the live/positive conductor and black lead to the neutral/negative conductor.
4. Read the measurement value from the LCD display once it stabilizes.
5. Turn the rotary switch to the "OFF" position to turn off the multimeter.

Resistance Measurement

1. Insert the red test lead into the Input jack (red) and the black test lead into the COM jack (black).
2. Turn the rotary switch to the "Ω" setting.
3. Connect the test leads to both ends of the resistor being tested, ensuring direct contact.
4. The results will appear on the LCD display.

Capacitance Measurement

1. Insert the red test lead into the Input jack (red) and the black test lead into the COM jack (black).
2. Turn the rotary switch to the "Ω" setting. Press the FUNC button to switch to capacitance measurement mode.
3. Connect the test leads directly across the terminals of the capacitor.
4. The measurement results will appear on the LCD display.

Continuity Test

1. Ensure the circuit being tested is de-energized.
2. Insert the red test lead into the Input jack (red) and the black test lead into the COM jack (black).
3. Turn the multimeter on by setting the rotary switch to the "))) " symbol. Touch the two test probes together to ensure they are functioning; a tone should sound.
4. Connect the test leads to both sides of the object being tested. If there is continuity, the buzzer will sound, and the Status LED will light green. The display will show a resistance value. If there is no continuity, the buzzer will not sound, and the display will show "OL" (indicating infinite resistance).

Diode Test

1. Insert the red test lead into the Input jack (red) and the black test lead into the COM jack (black).
2. Turn the rotary switch to the "➡️+" setting. Press the FUNC button to switch to diode testing mode.
3. Connect the red test lead to the positive side of the diode and the black test lead to the negative side of the diode.
4. The LCD display will show the measured forward voltage drop across the diode. If the test leads are connected incorrectly to the diode's electrodes, the display will show "OL".

Battery Test

1. Insert the red test lead into the Input jack (red) and the black test lead into the COM jack (black).
2. Set the rotary switch to the battery test setting to test 1.5 V, 9 V, and 12 V batteries.
3. Connect the red test lead to the positive electrode and the black test lead to the negative electrode of the battery.
4. Read the measurement value from the LCD display once it stabilizes. If the battery voltage is low, the Status LED will light red.

NOTE: Do not test batteries directly with current or resistance settings.

Current Measurement

1. Turn the rotary switch to the "mA≈" or "A≈" setting, depending on the expected current.
2. Press the FUNC button to switch between AC and DC current.
3. For "mA≈" settings, insert the red test lead into the "mA" jack (red) and the black test lead into the "COM" jack (black).
4. For "A≈" settings, insert the red test lead into the "10 A" jack (red) and the black test lead into the "COM" jack (black).
5. Disconnect the power source from the circuit to be tested. Connect the multimeter in series with the circuit, then turn on the circuit's power source.
6. The measurement result will then appear on the LCD display.

Non-Contact Voltage (NCV) Detection

The NCV function detects AC voltages without the need for test leads.

1. Set the rotary switch to the NCV function ("NCV" / "Live").
2. Bring the NCV detector close to the area to be tested.
3. If the multimeter detects a weak AC voltage signal, the green Status LED will light up, and the buzzer will emit a slow beep.
4. If the multimeter detects a strong AC voltage signal, the red Status LED will light up, and the buzzer will emit a fast beep.

Live Wire Detection

This function detects live wires using the red test lead.

1. Insert the red test lead into the "Input" jack (red). The black test lead should not be connected to any jack.
2. Turn the rotary switch to the "NCV" / "Live" setting. Press the FUNC button to switch to live wire detection mode; "Live" will be displayed.
3. Touch the probe of the red test lead to the suspected live wire.
4. If the multimeter detects a weak AC voltage signal, the green Status LED will light up, and the buzzer will emit a slow beep.
5. If the multimeter detects a strong AC voltage signal, the red Status LED will light up, and the buzzer will emit a fast beep.

Maintenance

Battery Replacement

When the low battery indicator appears on the LCD display, replace the batteries. Remove the rubber cover, loosen the screws on the rear cover, and replace the depleted batteries with new ones (Size AAA, 1.5 V x 2).

Fuse Replacement

Fuses rarely need replacement and usually blow due to user error. To replace a fuse:

• Pull out the test leads.
• Remove the rubber sleeve and the screws on the rear cover of the multimeter.
• Open the rear of the multimeter and replace the fuses with fuses of the same specifications.

It is essential that replacement fuses have the same rating:

• Fuse 1: F400 mA / 250 V, 5 mm×20 mm.
• Fuse 2: F10 A / 250 V, 5 mm×20 mm.

Detailed Specifications

DC Voltage

AC Voltage

DC Current

AC Current

Resistance

Capacitance

Battery

Warranty

AstroAI offers a 3-year limited warranty on this digital multimeter, covering defects in material or workmanship. This warranty does not cover fuses, disposable batteries, or damage resulting from negligence, improper use, contamination, modification, accidents, or abnormal conditions, including overvoltage damage from measurements outside specified ranges, nor normal wear and tear of mechanical components. This warranty is valid only for the original purchaser and is non-transferable.

Should this product be defective, please contact AstroAI Customer Service via support@astroai.com.

Contact Information

Web: www.astroai.com

E-mail: support@astroai.com

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