MASTFUYI FY125 Digital Multimeter User Manual
Product image: A handheld digital multimeter with a screen and dial.
Safety Information
Important Safety Precautions:
- Read this manual carefully before use.
- Use only in accordance with specified measurement categories (e.g., CAT II, CAT III).
- Do not exceed maximum input voltage or current ratings.
- Inspect the multimeter and test leads for damage before each use.
- Ensure proper insulation and avoid contact with live circuits unless properly protected.
- Disconnect power before replacing fuses or batteries.
- Do not operate in explosive or flammable environments.
- Observe all safety symbols: ⚡ (High Voltage), ⚠️ (Caution), [Double Insulation] (Double Insulation).
General Precautions
- Keep the device dry and away from moisture.
- Avoid exposure to strong magnetic fields.
- Do not expose to extreme temperatures or direct sunlight for prolonged periods.
- Handle the device with care to prevent damage.
Features
- Auto-ranging for convenient measurement.
- True RMS (Root Mean Square) for accurate AC measurements.
- NCV (Non-Contact Voltage) detection.
- High safety design for user protection.
- Backlit LCD display for easy reading in low light.
- Data Hold function to freeze readings.
- Low battery indicator ?.
Specifications
DC Voltage:
| Range | Accuracy | Resolution |
|---|---|---|
| 600mV | ±(0.5%+3) | 0.1mV |
| 6V/60V/600V | ±(0.5%+3) | 1mV/10mV/100mV |
AC Voltage:
| Range | Accuracy | Resolution |
|---|---|---|
| 600mV | ±(1.0%+3) | 0.1mV |
| 6V/60V/600V | ±(1.0%+3) | 1mV/10mV/100mV |
DC Current:
| Range | Accuracy | Resolution |
|---|---|---|
| 60mA/600mA | ±(1.0%+3) | 0.01mA/0.1mA |
| 10A | ±(2.0%+3) | 10mA |
AC Current:
| Range | Accuracy | Resolution |
|---|---|---|
| 60mA/600mA | ±(1.5%+3) | 0.01mA/0.1mA |
| 10A | ±(2.5%+3) | 10mA |
Resistance:
| Range | Accuracy | Resolution |
|---|---|---|
| 600Ω | ±(1.0%+3) | 0.1Ω |
| 6kΩ/60kΩ/600kΩ | ±(1.0%+3) | 1Ω/10Ω/100Ω |
| 6MΩ | ±(1.5%+3) | 1kΩ |
Continuity Test: Audible beep for resistance < 30Ω.
NCV Detection: Yes.
Power Source: 1 x 9V Battery (included).
Dimensions: Approx. 150mm x 80mm.
Safety Rating: CAT III 600V, CAT II 1000V.
Operating Instructions
1. Power On/Off: Press the power button to turn the multimeter on. The device features auto-power off after a period of inactivity.
2. Selecting Measurement Function: Rotate the central dial to choose the desired measurement type (e.g., V~ for AC Voltage, V- for DC Voltage, Ω for Resistance, A for Current).
3. Connecting Test Leads:
- Insert the black test lead into the COM terminal.
- Insert the red test lead into the appropriate terminal: VΩmA for voltage, resistance, current up to 600mA; 10A for current up to 10A.
4. Performing Measurements:
- Voltage: Connect the test leads in parallel across the voltage source.
- Current: Connect the test leads in series with the circuit. Ensure the correct current input terminal is used.
- Resistance: Connect the test leads across the component. Ensure the circuit is de-energized.
- Continuity: Connect leads across the component. A beep indicates continuity.
- NCV Detection: Select NCV mode. Bring the multimeter tip near a conductor. The device will indicate voltage presence.
5. Using Data Hold: Press the HOLD button to capture and display the current reading. Press again to resume normal measurement.
6. Using Backlight: Press the backlight button to activate or deactivate the display illumination.
Diagram Descriptions
Diagram 1: Front Panel Layout
Depicts the multimeter with its LCD display, rotary dial for function selection, buttons for HOLD, SELECT, RANGE, and backlight, and input jacks labeled COM, VΩmA, and 10A.
Diagram 2: Voltage Measurement Setup
Illustrates connecting the black probe to COM and the red probe to VΩmA to measure DC voltage across a battery, showing parallel connection.
Diagram 3: Current Measurement Setup
Shows connecting the black probe to COM and the red probe to the A jack for series connection in a circuit to measure current.
Diagram 4: Resistance Measurement Setup
Demonstrates connecting the black probe to COM and the red probe to VΩmA to measure resistance across a resistor.
Diagram 5: NCV Detection
Shows the multimeter tip near a live wire, indicating the NCV function is active and detecting voltage.
Diagram 6: Continuity Test
Illustrates connecting the probes for continuity testing, with an indication of the audible beep.
Troubleshooting
No Power: Check battery installation and ensure it is charged. Replace if necessary.
Inaccurate Readings: Ensure test leads are securely connected to the correct terminals. Check for damaged leads or probes. Verify the selected function and range. Ensure the circuit is stable.
Continuity Beep Not Sounding: Check resistance reading; if it's high, there is no continuity. Ensure probes are making good contact.
Maintenance
Battery Replacement: When the low battery indicator ? appears, replace the 9V battery. Open the battery compartment cover, remove the old battery, and insert a new one, observing polarity.
Fuse Replacement: If the multimeter fails to measure current, the fuse may be blown. Disconnect all test leads and open the fuse cover. Replace with the specified fuse type (e.g., F 500mA/250V for mA range, F 10A/250V for A range). Ensure correct fuse rating is used.
About MASTFUYI
MASTFUYI is committed to providing reliable and accurate measurement tools for professionals and hobbyists alike. For support or more information, please visit the MASTFUYI website or contact authorized distributors.
