Aneng DM850 Digital Multimeter User Manual

1. Introduction

Thank you for choosing the Aneng DM850 Digital Multimeter. This manual provides essential information for the safe and effective operation, maintenance, and troubleshooting of your device. Please read this manual thoroughly before use and keep it for future reference.

The Aneng DM850 is a compact, battery-powered, handheld digital multimeter designed for measuring AC/DC voltage, DC current, resistance, diode, continuity, and hFE (transistor gain). It is suitable for professional, factory, school, and hobbyist use.

2. Safety Information

To ensure safe operation and service of the meter, follow these instructions carefully. Failure to observe these safety warnings may result in severe injury or damage to the meter.

• Always ensure the meter is in the correct function and range before making measurements.
• Do not apply more than the rated voltage, as marked on the meter, between the terminals or between any terminal and earth ground.
• Use caution when working with voltages above 30V AC RMS, 42V peak, or 60V DC. These voltages pose a shock hazard.
• Disconnect the test leads from the circuit before changing functions.
• Do not operate the meter if it appears damaged or if the case is open.
• Replace the battery as soon as the low battery indicator appears to ensure accurate readings.
• Always use approved test leads with finger guards.

Safety Symbols:

• ⚠: Caution, risk of electric shock.
• ⚠: Caution, refer to this manual.
• ☑: Double insulation.
• CAT II: Overvoltage Category II.

3. Product Overview

The Aneng DM850 Digital Multimeter features a clear LCD display, a rotary function switch, and multiple input jacks for various measurements.

Figure 3.1: Front view of the Aneng DM850 Digital Multimeter. This image displays the device's LCD screen, rotary function switch, input jacks (VÅmA, COM, 10A), and the 'HOLD' button. The various measurement ranges and functions are clearly labeled around the rotary switch.

Key Components:

1. LCD Display: Shows measurement readings, units, and function indicators.
2. HOLD Button: Freezes the current reading on the display.
3. Rotary Function Switch: Selects the desired measurement function and range.
4. VÅmA Jack: Input for voltage, resistance, diode, continuity, and low current measurements.
5. COM Jack: Common (negative) input for all measurements.
6. 10A Jack: Input for high DC current measurements (up to 10A).

4. Setup

4.1 Battery Installation

The Aneng DM850 requires a 9V battery (NEDA 1604 or 6F22 type). To install or replace the battery:

1. Ensure the multimeter is turned OFF and disconnect all test leads.
2. Locate the battery compartment cover on the back of the unit.
3. Remove the screw(s) securing the cover and gently lift it off.
4. Connect the 9V battery to the battery clip, observing correct polarity.
5. Place the battery into the compartment and replace the cover, securing it with the screw(s).

4.2 Connecting Test Leads

Always use the provided test leads. Ensure they are in good condition with no cracked or broken insulation.

• Insert the black test lead into the COM (common) jack.
• Insert the red test lead into the VÅmA jack for voltage, resistance, diode, continuity, and low current measurements.
• For high DC current measurements (up to 10A), insert the red test lead into the 10A jack.

5. Operating Instructions

Before taking any measurement, ensure the test leads are correctly connected and the function switch is set to the appropriate range.

5.1 DC Voltage Measurement (V—)

1. Set the rotary switch to the desired DC Voltage (V—) range (e.g., 200mV, 2V, 20V, 200V, 600V). If the voltage is unknown, start with the highest range and decrease as needed.
2. Connect the red test lead to the positive side of the circuit and the black test lead to the negative side.
3. Read the voltage value on the LCD display. If a negative sign appears, it indicates reversed polarity.

5.2 AC Voltage Measurement (V∼)

1. Set the rotary switch to the desired AC Voltage (V∼) range (e.g., 200V, 600V).
2. Connect the test leads across the AC voltage source.
3. Read the voltage value on the LCD display.

5.3 DC Current Measurement (A—)

Caution: Never connect the multimeter in parallel with a voltage source when measuring current, as this can blow the fuse or damage the meter.

1. Determine the approximate current to be measured. For currents up to 200mA, use the VÅmA jack. For currents up to 10A, use the 10A jack.
2. Set the rotary switch to the appropriate DC Current (A—) range (e.g., 2mA, 20mA, 200mA, 10A).
3. Open the circuit where the current is to be measured.
4. Connect the multimeter in series with the circuit, ensuring the red lead is towards the higher potential and the black lead towards the lower potential.
5. Read the current value on the LCD display.

5.4 Resistance Measurement (Ω)

Caution: Ensure the circuit under test is completely de-energized before measuring resistance. Disconnect power and discharge all capacitors.

1. Set the rotary switch to the desired Resistance (Ω) range (e.g., 200Ω, 2kΩ, 20kΩ, 200kΩ, 2MΩ).
2. Connect the test leads across the component or circuit segment to be measured.
3. Read the resistance value on the LCD display.

5.5 Diode Test (→|←)

1. Set the rotary switch to the Diode Test (→|←) position.
2. Connect the red test lead to the anode and the black test lead to the cathode of the diode. The display will show the forward voltage drop (typically 0.5V to 0.8V for silicon diodes).
3. Reverse the test leads. The display should show 'OL' (Open Loop) for a good diode. If it shows a reading, the diode is likely shorted. If it shows 'OL' in both directions, the diode is open.

5.6 Continuity Test (♫)

1. Set the rotary switch to the Continuity Test (♫) position.
2. Connect the test leads across the circuit or component.
3. If the resistance is below approximately 50Ω, the built-in buzzer will sound, indicating continuity. The display will also show the resistance value.

5.7 hFE Test (Transistor Gain)

1. Set the rotary switch to the hFE position.
2. Identify the type of transistor (NPN or PNP) and its emitter, base, and collector leads.
3. Insert the transistor leads into the corresponding sockets in the hFE test socket on the multimeter.
4. Read the hFE value (DC current gain) on the LCD display.

5.8 Data Hold Function

Press the 'HOLD' button to freeze the current reading on the display. Press it again to release the hold function and resume live measurements.

6. Maintenance

6.1 Cleaning

Wipe the case with a damp cloth and mild detergent. Do not use abrasives or solvents. Keep the input terminals free from dirt and moisture.

6.2 Battery Replacement

When the battery symbol appears on the LCD, the battery needs to be replaced. Refer to Section 4.1 for battery installation instructions.

6.3 Fuse Replacement

If the current measurement function does not work, the fuse may be blown. To replace the fuse:

1. Ensure the multimeter is turned OFF and disconnect all test leads.
2. Remove the battery compartment cover (refer to Section 4.1).
3. Carefully remove the old fuse.
4. Replace with a fuse of the same type and rating (e.g., F200mA/250V for mA range, F10A/250V for 10A range).
5. Replace the battery and the compartment cover.

7. Troubleshooting

8. Specifications

9. Warranty and Support

This product is backed by a commitment to quality and customer satisfaction. While specific warranty terms may vary, we offer a money-back guarantee, reflecting our confidence in the product's performance.

For any questions, technical assistance, or support needs, please contact our customer service team. We pride ourselves on providing exceptional customer support with a knowledgeable team available to assist you.

Please refer to your purchase documentation or the seller's information for specific warranty periods and contact details.