1. Introduction
The UNI-T LM320 series digital angle meters are lightweight and portable instruments designed for precise angle measurements. Featuring a durable aluminum alloy frame (LM320D/E/F) or PC+GF material (LM320C) and a high-definition color display, these devices offer a full 4×90° measurement range. They provide real-time tilt angle data and are equipped with magnetic bases for stable positioning on metallic surfaces. The LM320 series is widely applicable in various fields including engineering, construction, and mechanical installation.
Key features include automatic screen rotation, relative/absolute measurement modes, data hold, and unit switching. Models LM320E and LM320F also incorporate laser lines for enhanced positioning accuracy.
2. Safety Information
- Read all instructions carefully before using the device.
- Do not attempt to disassemble or modify the device, as this may void the warranty and cause damage.
- Keep the device away from water and high humidity environments.
- Avoid direct exposure to the laser beam (for LM320E/F models) as it can cause eye injury.
- Store the device out of reach of children.
- Use only specified batteries or charging cables.
3. Package Contents
Upon unpacking, please verify that all items listed below are present and undamaged:
- Digital Angle Meter (Main Unit) x1
- User Manual x1
- Gift Box x1
- Type-C Charging Cable x1 (for LM320D, LM320E, LM320F models only)
- Iron Plate x1 (for models with magnetic base)
Note: LM320C model requires 2xAAA 1.5V batteries, which are not included and does not come with a Type-C cable.
4. Specifications
| Feature | LM320C | LM320D | LM320E | LM320F |
|---|---|---|---|---|
| Measurement Range | 4×90° | 4×90° | 4×90° | 4×90° |
| Resolution | ±0.05° | ±0.05° | ±0.05° | ±0.05° |
| Angle Accuracy | ±0.2° | ±0.2° | ±0.2° | ±0.2° |
| Repeatability | ±0.2° | ±0.2° | ±0.2° | ±0.2° |
| Units | ° / % | ° / % / mm/m / in/ft | ||
| Laser Lines | N/A | N/A | 2 lines | 3 lines |
| Laser Accuracy | N/A | N/A | ±3mm/5m | |
| Magnetic Base | 3 sides | 2 sides (Bottom & Rear) | 4 sides (Bottom, Rear, Left & Right) | |
| Relative/Absolute Angle Measurement | √ | √ | √ | √ |
| Angle Hold | √ | √ | √ | √ |
| Screen Rotation | √ | √ | √ | √ |
| Auto Power Off | 3 min inactivity | 5 min inactivity | ||
| Materials | PC+15%GF | Al-alloy frame + ABS | ||
| Power Supply | 2xAAA 1.5V batteries (not included) | 1000mAh lithium battery | ||
| Working Temperature | 0℃ ~ +40℃ | 0℃ ~ +50℃ | ||
| Laser Class | N/A | N/A | Class 2 | |
| Laser Type | N/A | N/A | 630-670nm, <1mW | |
| Battery Life | N/A | 14h | 8h | 6h |
| Product Size | 62x62x25mm | 83.5x70x35.5mm | ||
| Product Net Weight | Approx. 88g | Approx. 180g | ||
5. Setup
5.1. Battery Installation (LM320C)
- Locate the battery compartment cover on the back of the device.
- Open the cover and insert two (2) AAA 1.5V batteries, ensuring correct polarity (+/-).
- Close the battery compartment cover securely.
5.2. Charging (LM320D, LM320E, LM320F)
These models are equipped with a built-in 1000mAh rechargeable lithium battery.
- Connect the provided Type-C charging cable to the charging port on the device.
- Connect the other end of the cable to a standard USB power adapter (not included) or a computer USB port.
- The battery indicator on the display will show charging status. Charge until the battery is full.
5.3. Power On/Off
Press the Power button (usually marked with a power symbol) to turn the device on or off.
6. Operation
6.1. Basic Angle Measurement
Place the digital angle meter firmly on the surface or object whose angle you wish to measure. The current angle will be displayed on the screen. The display automatically rotates for easy viewing in any orientation.
6.2. Relative and Absolute Measurement Modes
The device supports both relative (REF) and absolute (ABS) measurement modes.
- Absolute Mode (ABS): Measures the angle relative to a true horizontal plane (0°).
- Relative Mode (REF): Allows you to set any surface as a temporary zero reference. To activate, place the device on your desired reference surface and press the REF/ABS button. The display will show 0.00. Subsequent measurements will be relative to this new zero point.
6.3. Unit Switching (LM320D, LM320E, LM320F)
Press the UNIT button to cycle through the available measurement units: degrees (°), percentage (%), millimeters per meter (mm/m), and inches per foot (in/ft).
6.4. Data Hold
To freeze the current measurement on the display for easier reading, press the HOLD button. Press it again to release the hold function and resume live measurement.
6.5. Laser Function (LM320E, LM320F only)
Models LM320E and LM320F are equipped with laser lines for precise alignment and positioning.
- Press the LASER button to activate the laser lines.
- The LM320E features two-side lasers, while the LM320F features three-side lasers for more comprehensive positioning.
- Press the LASER button again to turn off the lasers.
6.6. Calibration
To ensure accuracy, it is recommended to calibrate the device periodically or if you suspect inaccurate readings.
- Place the device on a perfectly horizontal and stable surface.
- Long press the REF/ABS button three times consecutively. The display will show "CAL0".
- Follow the on-screen prompts (e.g., CAL1, CAL2) by rotating the device 90 degrees as instructed. The device will guide you through the calibration process.
- Once calibration is complete, the device will return to normal measurement mode.
7. Maintenance
- Cleaning: Wipe the device with a soft, dry cloth. Do not use abrasive cleaners, solvents, or corrosive chemicals.
- Storage: Store the angle meter in a cool, dry place, away from direct sunlight and extreme temperatures. If the LM320C model is not used for an extended period, remove the AAA batteries to prevent leakage.
- Battery Care (LM320D/E/F): Recharge the lithium battery regularly, even if the device is not in frequent use, to maintain battery health.
8. Troubleshooting
- Device does not power on:
- For LM320C: Check if the AAA batteries are installed correctly and have sufficient charge. Replace if necessary.
- For LM320D/E/F: Ensure the built-in lithium battery is charged. Connect to a power source using the Type-C cable. - Inaccurate readings:
- Ensure the measurement surface is stable and free from vibrations.
- Perform a calibration as described in Section 6.6. - "Error" message on display: This typically indicates a need for calibration. Follow the calibration steps in Section 6.6.
- Laser not working (LM320E/F): Check battery level. Ensure the LASER button has been pressed.
9. User Tips
- For critical measurements, always perform a quick calibration to ensure optimal accuracy.
- Utilize the magnetic base (available on all models, with varying sides) for hands-free operation on metallic surfaces, which can greatly improve stability and precision.
- The data hold function is particularly useful when taking measurements in awkward or hard-to-see locations.
- When using the laser function (LM320E/F), ensure the laser line is clearly visible on the target surface for accurate alignment.
10. Applications
The UNI-T LM320 series digital angle meters are versatile tools suitable for a wide range of applications, including but not limited to:
- Building construction and renovation
- Bridge engineering and structural alignment
- Mechanical installation and machinery setup
- Desktop installation and leveling
- Hanging decoration installation (e.g., picture frames, shelves)
- Rail inspection and maintenance
- Woodworking and metalworking projects
- Automotive maintenance and alignment
11. Warranty and Support
For warranty information, technical support, or service inquiries, please refer to the warranty card included in your package or contact the retailer/manufacturer directly. Keep your purchase receipt as proof of purchase.