1. Introduction
The Victor 921A/921B Digital Multimeter is a super thin, 3 5/6-bit automatic digital instrument designed for precise electrical measurements. It offers stable performance, high accuracy, and high reliability, featuring a clear large screen display and comprehensive overload protection. Powered by a single AAA 1.5V battery, this meter is easy to carry and suitable for various electrical testing needs.
2. Safety Information
To ensure safe operation and avoid damage to the meter, please read this manual carefully before use and observe all safety warnings. Improper use can lead to electric shock or damage to the instrument.
- Always ensure the test leads are in good condition, free from cracks or damage.
- Do not apply voltage or current that exceeds the maximum specified limits for the meter.
- Exercise extreme caution when working with voltages above 30V AC RMS, 42V peak, or 60V DC. These voltages pose a shock hazard.
- Before measuring current, ensure the meter is connected in series with the load and the circuit is de-energized.
- Before measuring resistance, capacitance, or diode, ensure the circuit under test is de-energized and all capacitors are discharged.
- Replace the battery immediately when the low battery indicator appears to ensure accurate readings.
- Do not operate the meter in explosive gas, vapor, or dusty environments.
- Adhere to the CAT II 600V safety rating.
3. Product Overview
The Victor 921A/921B multimeters are compact and feature a clear digital display. The 921B model includes a VA color screen for enhanced visibility and offers both automatic and manual measurement modes.
3.1 Key Features
- Automatic Range (Auto Range)
- Live Wire Judgment (LIVE)
- Capacitance Measurement
- Resistance Measurement
- AC/DC Voltage Measurement
- Non-Contact Voltage (NCV) Measurement
- Diode Test
- Flashlight Lighting
- True RMS Measurement
- Data Hold Function
- Low Battery Prompt
- Large Screen Display
- Automatic Shut-down
3.2 Components and Display
- LED Indicator: Status light.
- Protective Leather Case: Provides durability and grip.
- Display Screen: Digital readout (Common screen for 921A, VA color screen for 921B).
- NCV / Zero Live Line: Sensor area for non-contact voltage and live wire detection.
- Power Button: To turn the device on/off.
- Data Hold Button (HOLD): Freezes the current reading on the display.
- Flashlight Button: Activates the built-in flashlight.
- Function Buttons: For selecting specific measurement modes (e.g., SMART FUNC for 921B).
- Input Jacks: Red and Black test pen jacks for connecting test leads.
4. Specifications
| Parameter | 921A | 921B |
|---|---|---|
| Measurement Mode | Full automatic | Full automatic/manual operation |
| DC Voltage | 0.1mV-600V (0.8%±5) | 0.1mV-600V (0.8%±5) |
| AC Voltage | 1mV-600V (1.0%±3) | 1mV-600V (1.0%±3) |
| Resistance | 1Ω-60MΩ (1.5%±2) | 1Ω-60MΩ (1.5%±2) |
| Frequency | 40Hz-5999Hz | 40Hz-1kHz |
| Capacitance | 0.1uF-60000uF | 0.1uF-60000uF |
| Diode | ✓ | ✓ |
| On/Off Beep | Sounding less than 50Ω | Sounding less than 50Ω |
| NCV Voltage Sensing | ✓ | ✓ |
| Null Live Wire Identification | ✓ | ✓ |
| Environmental Temperature Measurement | 0℃-40℃ | 0℃-40℃ |
| Flashlight Lighting | ✓ | ✓ |
| Numerical Locking | ✓ | ✓ |
| Low Voltage Prompt | ✓ | ✓ |
| Over Range Prompt | OL | OL |
| Positive and Negative Polarity Prompt | ✓ | ✓ |
| Analog Bar | 21 segments | 21 segments |
| Sampling Rate | About three times per second | About three times per second |
| Display Count | 5999 counting | 5999 counting |
| Automatic Shut-down | Yes (can be cancelled manually) | Yes (can be cancelled manually) |
| Display Screen | Common screen | VA color screen |
| Weight | About 167g (including battery) | About 175g (including battery) |
| Power Supply | AAA battery x 1 | AAA battery x 1 |
| Dimensions | 148x76x19mm (length x width x height) | 148x76x19mm (length x width x height) |
| Certification | CE | CE |
5. Setup
5.1 Battery Installation
- Ensure the multimeter is powered off.
- Locate the battery compartment cover on the back of the device.
- Use a screwdriver to open the battery compartment.
- Insert one AAA 1.5V battery, observing the correct polarity (+/-).
- Close the battery compartment cover and secure it with the screw.
5.2 Connecting Test Leads
Insert the red test lead into the 'INPUT' jack and the black test lead into the 'COM' (common) jack. Ensure they are firmly seated before taking any measurements.
6. Operating Instructions
6.1 Power On/Off
Long press the power button (Power Icon) to turn the multimeter on or off.
6.2 Automatic / Manual Switching (VC921B only)
The Victor 921B model supports both automatic and manual measurement modes. Press the 'SMART FUNC' button to switch between these modes or to cycle through different functions within a category (e.g., AC/DC voltage).
6.3 Voltage Detection
After powering on, the multimeter can automatically detect voltage. Simply touch the test pen to the live wire, and the screen will immediately display the voltage value.
6.4 Null Live Wire Identification
To identify a null or live wire, use the NCV/Live function. The meter will indicate the presence of a live wire.
6.5 NCV Voltage Sensing
For non-contact voltage detection, bring the NCV sensor area of the multimeter close to the AC voltage source. The buzzer will emit an uninterrupted sound, and the analog bar on the display will show segments corresponding to the signal strength, indicating the presence of AC voltage.
6.6 Data Hold
Press the 'HOLD' button to freeze the current reading on the display. Press it again to release the hold function.
6.7 Flashlight
Press the flashlight button to turn on the built-in flashlight for illumination in dimly lit areas. Press again to turn it off.
6.8 True RMS Measurement
The multimeter features True RMS measurement, which provides accurate readings for non-sinusoidal AC waveforms, unlike traditional multimeters that only measure the average value of a sine wave.
7. Maintenance
- Cleaning: Use a soft, damp cloth to clean the meter's casing. Do not use abrasives or solvents.
- Battery Replacement: Replace the AAA 1.5V battery when the low battery indicator appears. Refer to section 5.1 for instructions.
- Storage: If the meter is not used for a long period, remove the battery to prevent leakage and store it in a cool, dry place.
- Calibration: For professional use, periodic calibration by qualified personnel is recommended to maintain accuracy.
8. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Meter does not power on | Dead or incorrectly installed battery | Check battery polarity or replace with a new AAA 1.5V battery. |
| No reading or 'OL' displayed | Open circuit, out of range, or incorrect function selected | Check test lead connections, ensure circuit is complete, select appropriate range/function. |
| Inaccurate readings | Low battery, damaged test leads, or environmental interference | Replace battery, inspect/replace test leads, move away from strong electromagnetic fields. |
| NCV/Live function not working | Weak signal or incorrect usage | Ensure the sensor is close enough to the AC source. |
9. User Tips
- For quick checks, the auto-ranging feature is very convenient, but for specific measurements, the manual mode (on 921B) can offer more control.
- The compact size makes it ideal for carrying in a pocket or tool belt for on-the-go diagnostics.
- Utilize the flashlight function when working in dark spaces to improve visibility and safety.
10. Warranty and Support
For warranty claims or technical support, please contact your retailer or the manufacturer directly. Keep your purchase receipt as proof of purchase. This product is certified with CE, indicating compliance with European safety standards.
For more information about the manufacturing process, you can view the official video: