Mastfuyi FY107C/FY107B Digital Multimeter Instruction Manual

1. Introduction

The Mastfuyi FY107C/FY107B handheld digital multimeter is a versatile and portable tool designed for accurate electrical measurements. Featuring a fast response time and an easy-to-read 3.3-inch large LCD display, it is suitable for use in educational settings, homes, factories, and by both professionals and hobbyists. This manual provides essential information for the safe and effective operation of your multimeter.

Figure 1: Mastfuyi Digital Multimeter (FY107B model shown) with included test leads.

2. Safety Information

Please read and understand all safety information before operating this multimeter. Failure to follow these instructions could result in electric shock, fire, or damage to the meter.

• Always ensure the multimeter is in the correct measurement mode before connecting to a circuit.
• Do not attempt to measure voltages or currents exceeding the specified maximum limits. This device has a Safety Level of 600V CAT III.
• Exercise extreme caution when working with live circuits.
• Inspect test leads for damage before each use. Do not use if insulation is cracked or the probe tips are exposed.
• The multimeter features a smart anti-burning design with 250V DC/AC overload protection, but proper usage is still critical.
• The device is designed for a Pollution Level of 2. Avoid using in excessively dirty or humid environments.
• Do not operate the meter if it appears damaged or is not functioning properly.
• Replace batteries immediately when the low battery indicator appears to ensure accurate readings.

3. Product Overview

3.1 Components

• Digital Multimeter Unit (FY107B or FY107C)
• Pair of Test Leads (Red and Black)
• Storage Bag
• Temperature K-type Probe (Included with FY107C Model Only)
• User Manual (English)

3.2 Display and Controls

The multimeter features a 3.3-inch HD large LCD display with a large white font, providing clear readouts even in dark environments.

Figure 2: Clear visibility of the 3.3-inch LCD display in various lighting conditions.

The front panel includes intuitive buttons for power, mode selection (SEL), data hold (HOLD), and NCV/Live line activation.

4. Specifications

Figure 3: The compact, pocket-sized design of the multimeter.

5. Setup

5.1 Battery Installation

The multimeter requires two 1.5V AAA batteries (not included).

1. Locate the battery compartment cover on the back of the multimeter.
2. Use a screwdriver to open the battery compartment.
3. Insert two AAA batteries, ensuring correct polarity (+ and -).
4. Replace the battery compartment cover and secure it with the screw.

5.2 Test Lead Connection

Connect the test leads to the appropriate input jacks on the multimeter.

• Insert the black test lead into the "COM" (Common) jack.
• Insert the red test lead into the "INPUT" jack (labeled VΩHz) for most measurements (voltage, resistance, frequency, capacitance, diode, continuity).

6. Operating Instructions

6.1 Power On/Off

Press the Power button (red circle with line) to turn the multimeter on or off. The device features a 15-minute auto-off function to conserve battery life if inactive.

6.2 Measurement Modes

The multimeter offers both auto-recognition and manual mode selection.

• Auto Measurement Mode: The multimeter automatically recognizes and measures DC/AC voltage, resistance, and continuity without manual switching. This is the default mode upon power-on.
• Manual Mode Selection: Press the SEL button to cycle through manual measurement functions such as DC/AC voltage, continuity buzzer, capacitance, diode, temperature (FY107C Model Only), live line recognition, and NCV.

Figure 4: Multimeter demonstrating auto-recognition for smart measurement.

6.3 Specific Measurement Functions

Refer to the diagram below for visual guidance on connecting test leads for various measurements.

Figure 5: Visual guide for AC/DC Voltage, Continuity, Resistance, Diode, Capacitance, NCV, and Live Line Tests.

• AC/DC Voltage Measurement: Select the appropriate voltage range (or use auto mode). Connect test leads in parallel to the circuit or component.
• Resistance Measurement: Ensure the circuit is de-energized. Connect test leads across the component.
• Capacitance Measurement: Ensure the capacitor is discharged. Connect test leads across the capacitor terminals.
• Frequency Measurement: Connect test leads to the signal source.
• Diode Test: Connect test leads across the diode. The display will show the forward voltage drop.
• Continuity Test: Connect test leads across the circuit path. A buzzer will sound if continuity is detected (resistance below 100Ω).
• NCV (Non-Contact Voltage) Test: Press the NCV LIVE button to activate NCV mode. Bring the top of the multimeter close to the conductor. The analog bar and buzzer will indicate signal strength (weak, median, strong).
  

  Figure 6: NCV test indicating signal strength with analog bar and buzzer.

• Live Line Recognition: Press the NCV LIVE button to activate Live mode. Insert the red test lead into the socket. The multimeter will display "LIVE" and sound a buzzer if a live line is detected.
  

  Figure 7: Live line recognition by inserting the test lead into a socket.
• Temperature Measurement (FY107C Model Only): Connect the K-type temperature probe to the multimeter. Place the probe tip on the object to be measured.

6.4 Data Hold

Press the HOLD button to freeze the current reading on the display. Press it again to release the hold function.

6.5 Flashlight

The multimeter is equipped with a flashlight for improved visibility in dimly lit work areas. (Specific activation method not detailed in provided data, assume a dedicated button or long-press of another button).

7. Maintenance

• Cleaning: Wipe the multimeter casing with a soft, damp cloth. Do not use abrasive cleaners or solvents.
• Battery Replacement: When the low battery indicator appears on the display, replace the two AAA batteries as described in Section 5.1.
• Storage: Store the multimeter in its provided storage bag in a dry environment, away from direct sunlight and extreme temperatures. The recommended storing temperature is -10~60℃.
• Test Leads: Regularly inspect test leads for any signs of wear or damage. Replace them if necessary to ensure safety and accurate measurements.

8. Troubleshooting

• No Display or Faint Display:
  • Check if the batteries are correctly installed and have sufficient charge. Replace if necessary.
  • Ensure the multimeter is powered on.
• Inaccurate Readings:
  • Verify that the test leads are properly connected to the correct input jacks.
  • Ensure the correct measurement mode is selected for the task.
  • Check for damaged test leads.
• Difficulty Reading LCD Display:
  • The super large LCD display is not a full-view angle screen. It is normal that you may not read the measured data clearly at some angles. Please tilt the meter slightly to find a clear viewing angle.
• "OL" Indication: This indicates an "Over Range" condition, meaning the measured value exceeds the selected range of the multimeter. Switch to a higher range or ensure the measurement is within the device's capabilities.

9. User Tips

• Keep Manual Handy: Always keep this instruction manual in a safe and accessible place for quick reference during operation or troubleshooting.
• Optimal Viewing Angle: If you find the display difficult to read, try adjusting the angle of the multimeter. The large LCD is not a full-view screen, so a slight tilt can significantly improve clarity.
• Battery Life: To maximize battery life, always turn off the multimeter when not in use, or rely on its 15-minute auto-off feature.
• Storage: Utilize the provided storage bag to protect your multimeter from dust and physical damage when not in use.

10. Warranty and Support

This product comes with a 1-year guarantee from the date of purchase. If your purchase does not meet merchantable quality, fitness for purpose, or match the description, please contact the seller or manufacturer for support.

For technical assistance or warranty claims, please refer to the contact information provided by your retailer or the manufacturer's official website.