AstroAI DM200M Digital Multimeter User Manual

Introduction

Thank you for purchasing the AstroAI DM200M 2000 Counts Digital Multimeter. AstroAI digital multimeters are designed to safely and accurately troubleshoot a wide range of automotive and home electrical issues in schools, laboratories, factories, and other areas. This manual provides all safety information, operation instructions, detailed specifications, and maintenance procedures for the meter. This instrument performs AC/DC Voltage, AC/DC Current, Resistance, NCV Detection, Diode, and Continuity Testing. Thank you again for choosing AstroAI. If you have any questions or concerns regarding your product, please contact AstroAI Customer Support at support@astroai.com.

⚠ Please fully read and understand this manual before using this product and keep this manual for future reference.

Important Safety Warnings

To avoid possible electric shock, personal injury, and other safety accidents, always adhere to the following rules:

• Please read through this manual before using this multimeter. Failure to follow the instructions may result in damaging or weakening the meter.
• Be cautious when measuring voltages beyond 60 V in DC, 30 V in AC RMS, or 42 V peak. There is a risk of getting shocked when working with these types of voltages.
• Do not measure voltages higher than the rated value between the terminals or between any terminal and grounding.
• Measure a known voltage to check whether the meter is working normally. Do not use it if the readings are incorrect or the meter is damaged.
• Before using the meter, inspect it for any defects. Do not use the meter if there are cracks or other damage to the plastic case.
• Inspect the test leads for any defects before using this product. If they are damaged, replace the test leads with those of the same model number and the same electrical specifications as the original.
• Always use this meter within the measurement ranges listed on the meter and in this manual.
• To avoid false readings, please replace the battery as soon as the low battery symbol ● appears on the screen. Using the meter with a low battery may cause inaccurate readings.
• Always comply with local and national safety regulations. Wear personal protective equipment (such as approved rubber gloves, masks, fireproof clothing, etc.) to prevent injury from electrical shocks and electric arcs when hazardous live conductors are exposed.
• Do not use the meter in an environment where there are explosive gasses/vapors present, or in high levels of humidity.
• When using the test leads, always keep your fingers behind the finger guards.
• When taking measurements, connect the neutral wire (ground) first. Then, connect the live wire. When disconnecting, remove the live wire first. Then, disconnect the neutral (ground) wire.
• Remove the test leads from the meter before opening its case or battery cover. Do not use the meter if it is disassembled or if the battery cover is open.
• To ensure safe operation, only use the meter with the included test leads. If the test leads are damaged and need to be replaced, they must be replaced with the same model number or identical electrical specifications as the original.
• To avoid damaging the meter, do not measure voltages exceeding 600 V DC or 600 V AC.
• To prevent electrical shocks or personal injury, exercise extra caution when measuring high voltages.
• Before using the meter, test a known voltage to confirm the meter is functioning normally.
• Please be cautious when measuring high voltages to avoid getting shocked and injured.
• To avoid damaging the meter or equipment, check the fuse before performing measurements and ensure that the measured current does not exceed the rated maximum current. Be sure to put the test leads into the correct terminal.
• Safely disconnect the power supply and discharge high-voltage capacitors before measuring resistors on a circuit board. Failure to do so may damage the meter and increase the risk of electrical shock.
• Safely disconnect the power supply and discharge high-voltage capacitors before measuring the meter's continuity. Failure to do so may damage the meter and increase the risk of electrical shock.
• Safely disconnect the power supply and discharge high-voltage capacitors before performing diode tests on the circuit board. Failure to do so may damage the meter and increase the risk of electrical shock.
• Please use fuses of the same or specified rating to prevent electrical shock, injury, or damage to the meter.

Warning: Always keep the inside of the meter clean and dry to prevent electrical shock or damage.

Warning: Replace the battery as soon as it gets low. This will help prevent false readings, electrical shocks, and even injuries. Do not discharge the battery by short-circuiting it or reversing its polarity.

Warning: To ensure safe operation and maintenance of the meter, remove the battery when not used for a long time. Doing so will prevent battery leakage and possible damage to the multimeter.

Included in Box

• User Manual x1
• Pair of Test Leads x1
• AstroAI 2000 Counts Multimeter x1

Electrical Symbols

Dimensions

Width: 5.59 inches (142 mm)

Height: 2.87 inches (73 mm)

Depth: 1.77 inches (45 mm)

Diagram: Multimeter Components

The AstroAI DM200M Digital Multimeter features the following key components:

• 1. Hold Button: Used to activate or deactivate the data hold function.
• 2. Function Switch Button: Used to switch between AC and DC current tests.
• 3. COM Terminal: The common terminal for test leads, typically connected to the negative or ground side of the circuit.
• 4. 10 A Terminal: A dedicated terminal for measuring high currents up to 10 Amperes.
• 5. Screen: The digital display showing measurement readings, symbols, and status.
• 6. Max Button: Turns the maximum value measurement mode on/off, capturing the highest reading.
• 7. Backlight Button: Turns the screen's backlight on or off.
• 8. Rotary Switch: Selects the measurement function (Voltage, Current, Resistance, etc.) and range.
• 9. VΩmA Terminal: The primary terminal for measuring voltage, resistance, and lower current ranges.
• 10. Test Leads: The probes used to connect the multimeter to the circuit under test.

Function Buttons

The multimeter is equipped with several function buttons:

• HOLD Function: Press the HOLD Button to activate or deactivate the data hold function, freezing the current reading on the screen.
• FUNC Function: Press the FUNC Button to switch between AC and DC current tests when the rotary switch is set to a current measurement range.
• MAX Function: Press the MAX Button to turn the maximum value measurement on/off. In this mode, the meter will capture and display the highest reading recorded during the measurement session.
• Backlight Function: Press this button to turn the screen's backlight on or off, improving visibility in low-light conditions.

Operating Instructions: Measuring DC/AC Voltage

1. Turn the rotary switch to the DC Voltage (V–) or AC Voltage (V~) setting and choose the appropriate voltage range.
2. Insert the red test lead into the "VΩmA" terminal and the black test lead into the "COM" terminal.
3. Connect the test leads to the circuit being tested in parallel. Ensure the red lead connects to the positive side and the black lead to the negative side.
4. The reading will appear on the screen.

Note: To avoid damaging the meter, do not measure voltages exceeding 600 V DC or 600 V AC. Exercise extra caution when measuring high voltages to prevent electrical shocks or personal injury. Before use, test a known voltage to confirm the meter is functioning normally.

Operating Instructions: Measuring DC/AC Current

1. Turn the rotary switch to the current setting (A– or A~) and choose the appropriate current range.
2. Insert the red test lead into the "VΩmA" terminal for lower currents (mA) or the "10A" terminal for higher currents (up to 10A), and the black test lead into the "COM" terminal.
3. Press the "FUNC" Button if necessary to select between DC/AC current measurement depending on the setting.
4. Disconnect the power supply of the circuit being tested. Connect the meter in series to the circuit being tested. Then, turn on the circuit's power supply.
5. The reading will be displayed on the screen.

Note: To avoid damaging the meter or equipment, check the fuse before performing measurements and ensure that the measured current does not exceed the rated maximum current. Be sure to insert the test leads into the correct terminal. When measuring high currents, the continuous measuring time should not exceed 15 seconds.

Operating Instructions: Measuring Resistance

1. Turn the rotary switch to the desired resistance setting (Ω) and choose the appropriate range.
2. Insert the red test lead into the "VΩmA" terminal and the black test lead into the "COM" terminal.
3. Connect the probes of the test leads to both ends of the resistor or circuit that needs to be measured.
4. The reading will be displayed on the screen.

Warning: Safely disconnect the power supply and discharge high-voltage capacitors before measuring resistors on a circuit board. Failure to do so may damage the meter and increase the risk of electrical shock.

Note: When measuring resistors on a circuit board, the reading may be affected by other electrical paths between the test leads.

Operating Instructions: Continuity Test

1. Turn the rotary switch to the Continuity Test (🔴 symbol) setting.
2. Insert the red test lead into the "VΩmA" terminal and the black test lead into the "COM" terminal.
3. Connect the probes of the test leads to both ends of the circuit or resistor that needs to be measured.
4. If the resistance value of the measured resistor or circuit is less than 50 Ω, the buzzer will beep. The screen will display the resistance value.

Warning: Safely disconnect the power supply and discharge high-voltage capacitors before measuring the meter's continuity. Failure to do so may damage the meter and increase the risk of electrical shock.

Note: When measuring the meter's continuity, the reading may be affected by other electrical paths between the test leads.

Operating Instructions: Diode Test

1. Turn the rotary switch to the Diode Test (📅 symbol) setting.
2. Insert the red test lead into the "VΩmA" terminal and the black test lead into the "COM" terminal.
3. Connect the red test lead to the positive end of the diode and the black test lead to the negative end.
4. The reading (forward voltage drop) will be displayed on the screen.

Warning: Safely disconnect the power supply and discharge high-voltage capacitors before performing diode tests on the circuit board. Failure to do so may damage the meter and increase the risk of electrical shock.

Note: When performing a diode test on the circuit board, the reading may be affected by other electrical paths between the test leads.

Operating Instructions: Non-Contact Voltage Test (NCV)

1. Turn the rotary switch to the "NCV" setting.
2. Gradually move the meter's NCV probe closer to the detected object.
3. When the meter senses a weak EMF signal, the "--L" character will appear on the screen, and the buzzer will emit a slow beep.
4. When the meter senses a strong EMF signal, the "--H" character will appear on the screen, and the buzzer will beep rapidly.

Maintenance: Auto Power Off

1. If the meter is on and not in use, it will shut off automatically after 15 minutes to preserve battery life. Press any button or turn the rotary switch to turn it back on.
2. To cancel the automatic power off function, press and hold the HOLD Button, then turn on the meter. To resume the automatic power off function, turn off the meter and then turn it back on.

Maintenance: Cleaning the Meter

If the terminals are dusty or wet, incorrect measurements may occur. Please clean the meter as follows:

1. Turn off the meter and remove the test leads.
2. Flip the meter over and shake out any dust that has built up in the terminals. Wipe the case with a damp cloth or mild detergent. Do not use abrasives or solvents. Wipe the contacts in each terminal with a clean cotton and alcohol.

Warning: Always keep the inside of the meter clean and dry to prevent electrical shock or damage.

Maintenance: Battery Replacement

1. Turn off the meter and remove the test leads.
2. Remove the screws on the battery cover with a screwdriver, then remove the cover.
3. Remove the old battery and replace it with a new battery of the same specification. Pay attention to the polarity markings (+ and –) for each battery in their compartments.
4. Put the battery cover back in its original position and secure it with its screws.

Warning: Replace the battery as soon as it gets low. This will help prevent false readings, electrical shocks, and even injuries. Do not discharge the battery by short-circuiting it or reversing its polarity.

Warning: To ensure safe operation and maintenance of the meter, remove the battery when not used for a long time. Doing so will prevent battery leakage and possible damage to the multimeter.

Maintenance: Fuse Replacement

1. Turn off the meter and remove the test leads.
2. Remove the screws on the meter's back cover, then remove the back cover.
3. Remove the blown fuses and replace them with new fuses of the same specification. Ensure the fuse is loaded into the fuse holder and clamped tightly.
4. Put the back cover back on and secure it with the removed screws.
5. Fuse specifications:
   • Fuse 1: F250 mA/250 V, 5 x 20 mm
   • Fuse 2: F10 A/250 V, 5 x 20 mm

Warning: Please use fuses of the same or specified rating to prevent electrical shock, injury, or damage to the meter.

Specifications

Detailed Specifications

Accuracy Note: Accuracy applies within one year after calibration.

Operating Conditions: The ambient temperature is between 64.4 °F to 82.4°F (18 °C to 28 ° C), and the relative humidity is less than or equal to 80%.

Accuracy: ± (% rdg + dgts) (rdg for reading and dgts for digits)

DC Voltage

Overload Protection: 600 V; Max Input Voltage: 600 V

Resistance

Overload Protection: 250 V

AC Voltage

Overload Protection: 600 V; Max Input Voltage: 600 V/40~400 Hz

DC/AC Current

Overload Protection: mA: F250 mA/250 V fuse A: F10 A/250 V
Max Input Current: 250 mA; 10 A
AC Current Frequency Range: 40 Hz ~ 400 Hz; Response: True RMS
When measuring high currents, the continuous measuring time does NOT exceed 15 seconds.

Continuity

Diode

Recycling

You may dispose of the product when its service life has ended. Please recycle the recyclable parts according to local guidelines.

Warranty Period

3-Year Limited Warranty from AstroAI.

Each AstroAI DM200M Digital Multimeter will be free from defects in material and workmanship.

This warranty does not cover fuses, disposable batteries and damage from neglect, misuse, contamination, alterations, accidents, or abnormal conditions of operation or handling, including overvoltage failures caused by use outside the multimeter's specified rating, or normal wear and tear of mechanical components. This warranty covers the original purchaser only and is not transferable.

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