1. Introduction
The UNI-T UT347A Leeb Hardness Tester is a precise and portable instrument designed for measuring the hardness of various metal materials. It features a 640x480 pixel display, thermal printing capabilities, and supports multiple hardness scales. This device is ideal for field hardness testing of large equipment such as roller turboshafts, pressure vessels, and turbine sets, finding extensive use in industries like petrochemical, electric power, automotive, shipbuilding, and machinery manufacturing.
Figure 1: UNI-T UT347A Leeb Hardness Tester with impact device and calibration block.
2. Safety Information
Please read and understand all safety instructions before operating the UT347A Leeb Hardness Tester. Failure to follow these instructions may result in injury or damage to the instrument.
- Always wear appropriate personal protective equipment (PPE) when conducting tests.
- Ensure the test surface is stable and secure to prevent movement during impact.
- Do not attempt to disassemble or modify the instrument. Refer all servicing to qualified personnel.
- Keep the instrument away from water, dust, and extreme temperatures.
- Use only the specified charging cable and power adapter.
- Avoid direct impact on sensitive electronic components or fragile materials.
3. Package Contents
Verify that all items are present and in good condition upon unpacking:
- UT347A Leeb Hardness Tester Main Unit
- Impact Device (D-type standard)
- Standard Hardness Block
- USB Type-C Cable
- Power Adapter (DC5V 2A)
- Cleaning Brush
- User Manual
- Carrying Case
4. Product Overview
Figure 2: Key features of the UT347A main unit, including LED lighting, camera, and rear lid bracket.
4.1 Key Features
- Display: 2.8-inch 320x240 graphic dot matrix color TFT screen with adjustable backlight.
- Hardness Scales: Supports HL, HB, HRC, HRB, HV, HS.
- Impact Devices: Compatible with 7 different impact devices (automatic identification without calibration).
- Measurement Modes: Statistical, Multi-unit, Line chart, Histogram.
- Data Storage: 900 groups of data storage and 900 groups of pictures storage (640x480 pixels BMP format).
- Connectivity: Mobile phone Bluetooth APP and PC software for data analysis and synchronization.
- Printing: Built-in thermal printer for real-time measurement printing (uses 57mm width thermal printing paper).
- Indicators: Tri-color LED indication (red, yellow, green) for alarm prompts.
- Additional Features: LED flashlight, voice prompt, auto power-off (1/5/10/30 minutes or cancel), low battery indication, 1m drop test rating.
Figure 3: Visual representation of the tester's main functions.
5. Setup
5.1 Charging the Battery
The UT347A is equipped with a built-in 3.7V 2500mAh polymer rechargeable lithium battery. Before initial use, fully charge the device.
- Connect the USB Type-C cable to the charging port on the side of the tester.
- Connect the other end of the cable to the provided DC5V 2A power adapter.
- Plug the power adapter into a suitable power outlet.
- The charging time is approximately 2-4 hours. The battery indicator on the display will show charging status.
Figure 4: Charging the UT347A Leeb Hardness Tester.
5.2 Connecting the Impact Device
The impact device is crucial for measurement. The UT347A automatically identifies the connected impact device.
- Locate the connector port on the side of the main unit.
- Align the connector of the impact device with the port and gently push it in until it clicks into place.
- Ensure a secure connection for accurate readings.
Figure 5: Connecting the impact device to the main unit.
5.3 Initial Settings
Upon first use or after a reset, you may need to configure basic settings.
- Language: The device supports multiple languages. Navigate to the settings menu to select your preferred language. (Note: The device supports English and other languages, including Spanish as per user queries).
- Date and Time: Set the correct date and time for accurate data logging.
- Auto Power-off: Configure the auto power-off duration (1, 5, 10, 30 minutes, or disabled) to conserve battery life.
6. Operating Instructions
6.1 Power On/Off
- To power on, press and hold the Power button.
- To power off, press and hold the Power button again until the device shuts down.
6.2 Self-Calibration Function
For optimal accuracy, especially after prolonged storage or before critical measurements, perform a self-calibration using the provided standard hardness block.
- Place the impact device firmly on the standard hardness block.
- Initiate the calibration sequence through the device menu.
- Perform five measurements on the standard block. The device will calculate the average and adjust its calibration based on the known hardness value of the block.
Figure 6: Self-calibration process.
6.3 Material Selection
The UT347A supports various material selections to ensure accurate hardness conversion. Select the appropriate material from the device menu before testing.
- Steel and cast steel
- Alloy tool steel
- Stainless steel
- Forged steel
- Cast aluminum alloy
- Copper zinc alloy
- Copper tin alloy
- Gray cast iron
- Nodular cast iron
- Pure copper
Figure 7: Material selection interface.
6.4 Impact Direction Selection
To obtain more accurate measurement results, the impact direction test settings can be adjusted to meet various scenarios. The device supports 0°, 45°, 90°, 135°, and 180° impact directions.
Figure 8: Available impact directions.
6.5 Performing a Measurement
- Ensure the impact device is properly connected and the device is powered on.
- Select the correct material and impact direction from the menu.
- Place the impact device firmly and perpendicularly on the test surface.
- Press the trigger button on the impact device to initiate the test. The hardness value will be displayed on the screen.
- Repeat measurements as needed for statistical analysis.
Figure 9: Examples of hardness testing on different materials.
6.6 Measurement Modes
The UT347A offers various measurement modes:
- Statistical Mode: Displays average, maximum, and minimum values of a series of measurements.
- Multi-unit Mode: Allows viewing results in different hardness scales simultaneously.
- Line Chart/Histogram: Visual representation of measurement data for analysis.
Figure 10: Statistical and Multi-unit measurement modes.
6.7 Data Storage and Photo Function
The device can store up to 900 groups of measurement data and 900 BMP format pictures (640x480 pixels).
- Access the data storage menu to review saved measurements.
- Use the built-in camera to capture images of the test area, which can be stored alongside measurement data.
Figure 11: Data storage interface.
Figure 12: Photo storage function.
6.8 Thermal Printing
The UT347A features a built-in thermal printer for immediate hard copies of your measurement results.
- Ensure thermal paper is loaded correctly into the printer slot.
- After completing measurements, select the print option from the device menu.
- The device will print the current measurement data.
Figure 13: Real-time measurement printing.
6.9 Alarm Settings
Set upper and lower limits for your measurements. The device will provide a visual alarm using tri-color LEDs if the readings fall outside the set range.
- Red LED: Indicates the measurement is below the lower limit.
- Green LED: Indicates the measurement is within the acceptable range.
- Orange LED: Indicates the measurement is above the upper limit.
Figure 14: Alarm setting and LED indications.
6.10 Connectivity (Bluetooth APP & PC Software)
The UT347A can connect to a mobile app via Bluetooth or to a PC via USB for advanced data analysis and management.
- Bluetooth APP: Download the official UNI-T app to your smartphone. Pair the device via Bluetooth to view, analyze, and export data.
- PC Software: Install the dedicated PC software. Connect the tester to your computer using the USB Type-C cable to synchronize data, generate reports, and perform further analysis.
Figure 15: PC software and mobile APP connectivity.
7. Maintenance
7.1 Cleaning
- Regularly clean the device and impact device with a soft, dry cloth.
- For the impact device, use the provided cleaning brush to remove any debris from the impact body.
- Do not use abrasive cleaners or solvents.
7.2 Battery Care
- Charge the battery regularly, even if the device is not in frequent use, to maintain battery health.
- Avoid fully discharging the battery for extended periods.
- If the device will not be used for a long time, charge it to about 50% and store it in a cool, dry place.
7.3 Storage
- Store the UT347A in its carrying case to protect it from dust, moisture, and physical damage.
- Keep the device in a dry environment with moderate temperatures.
8. Troubleshooting
- Device does not power on: Ensure the battery is charged. Connect to the charger and try again. If the issue persists, contact support.
- Inaccurate readings: Perform a self-calibration using the standard hardness block. Ensure the correct material and impact direction are selected. Check for proper contact between the impact device and the test surface.
- Printer not working: Check if thermal paper is loaded correctly and if there's enough paper. Ensure the printer head is clean.
- Bluetooth connection issues: Ensure Bluetooth is enabled on both the tester and your mobile device. Try restarting both devices.
- PC software not detecting device: Ensure the USB cable is securely connected and the PC software drivers are installed correctly.
9. Specifications
Figure 16: Detailed specifications of the UT347A Leeb Hardness Tester.
| Feature | Description |
|---|---|
| Model Number | UT347A |
| Display Type | DIGITAL (2.8-inch 320x240 graphic dot matrix color TFT screen) |
| Hardness Scale | HL, HB, HRC, HRB, HV, HS |
| Measuring Range | 170~960 HLD (with D-type impact device) |
| Impact Device Type | D (standard), DC, DL, D+15, G, E, C (interchangeable) |
| Data Storage | 900 groups (data and pictures) |
| Photo Storage | 640x480 pixels (BMP format) |
| Statistical Measure | Max/Min/Avg |
| Thermal Printing | 57mm width thermal printing paper |
| Voice Prompt | Yes |
| Bluetooth APP Function | Yes |
| USB Communication | Yes |
| PC Analysis Software | Yes |
| Auto Power Off | Can be set: 1/5/10/30 minutes or cancel |
| Low Battery Indication | Yes |
| External Power Source | DC5V 2A Type-C connector |
| Charging Time | About 2-4 hours |
| Battery | 3.7V 2500mAh polymer rechargeable lithium battery |
| Drop Test | 1m |
| Certifications | CE (In processing), UKCA |
10. User Tips
- Language Setting: The device supports multiple languages. If you prefer Spanish, navigate to the system settings menu to change the display language.
- Measuring Thin Materials: While the UT347A is versatile, measuring very thin materials with Leeb hardness testers can be challenging. Ensure the material thickness meets the minimum requirements for the selected impact device to get accurate readings. Consult the specifications for your specific impact device for minimum thickness guidelines.
- Surface Preparation: Always ensure the test surface is clean, smooth, and free of scale, oil, or other contaminants for reliable results.
11. Manufacturer Information
Video 1: UNI-T Corporate Overview - Showcasing commitment to quality and innovation in measurement instruments.
UNI-T (Uni-Trend Technology (China) Co., Ltd.) is a leading test and measurement solutions provider. Committed to assuring the safety and well-being of the community, UNI-T strives to bring innovative and cost-effective products to customers worldwide. Every production step strictly follows AOL international standards, striving for excellence.
