1. Overview
The UNI-T UT343D is an advanced coating thickness gauge designed for precise, non-destructive measurement of coating thickness on both ferrous (Fe) and non-ferrous (NFe) matrixes. It offers high precision, stable performance, and a range of features including an automotive mode, voice broadcast, Bluetooth APP connectivity, and an LED flashlight. This device is essential for various industries such as automotive manufacturing, sales, metal processing, painting, and quality inspection.
The gauge operates on two principles:
- Electromagnetic Induction (Fe): Measures coating thickness on ferromagnetic metals (e.g., iron, steel) by detecting the magnetic flux.
- Eddy Current Measurement (NFe): Measures non-conductive coatings on non-magnetic metals (e.g., aluminum, copper) by analyzing eddy currents.
The UT343D automatically identifies the matrix type (ferrous or non-ferrous) and supports a measurement range of 0-1250µm.
2. Safety Instructions
- When powering on, ensure the gauge's sensor is not near any metal objects to prevent usability issues.
- Keep the sensor clean and in good condition, free from dust, oil, or other factors that could affect measurement accuracy.
- Avoid using or storing the gauge in environments with high temperatures, high humidity, flammable, explosive materials, or strong magnetic fields.
- Clean the casing with a soft cloth and mild detergent. Do not use abrasive cleaners or solvents.
- Do not disassemble or modify the gauge.
- If the low battery symbol appears on the LCD, charge the product promptly.
- When using the USB interface for charging or data communication, use the original USB cable and disconnect it promptly after use.
- Do not shine the flashlight directly into eyes.
- For Bluetooth communication, maintain a distance of less than 10 meters between the gauge and the mobile device, and ensure no obstacles or metal shielding.
- Preserve standard coating thickness sheets and metal matrixes properly to prevent damage that could affect accuracy.
- If other failures occur, consider restoring factory settings.
3. Product Components and Structure
The UT343D Coating Thickness Gauge features a user-friendly design with clear controls and a vibrant display.
Figure 1: Detailed view of UNI-T UT343D Coating Thickness Gauge with labeled components.
3.1. Product Structure
- LED warning light
- LCD display
- Power button
- OK / Menu button
- Undo / Delete button
- Value minus button
- Value plus button
- Sensor assembly
- Hand rope hang buckle
- USB communication interface
3.2. Display Interface
The gauge features a 2-inch color TFT LCD display. The screen can automatically rotate to provide optimal viewing angles (0°, 90°, 180°, 270°), or it can be manually locked. The display shows measured values, statistical data (Avg, Min, Max, Sdev), unit, matrix type (Fe/NFe), and alarm indicators.
Figure 2: Main display interface of the UT343D.
4. Setup and Calibration
4.1. Power On/Off
To power on or off the gauge, long press the power button.
4.2. Calibration
Calibration is crucial for accurate measurements. If the gauge has not been used for a long time or the operating environment has changed, a two-point calibration is recommended.
In the main interface, long press the OK/Menu button to enter the selected calibration mode. The selected calibration mode depends on the setting in the menu (see section 5.2.10).
4.2.1. Zero-Point Calibration
- Place the gauge vertically on an uncoated metal matrix.
- Hold for 2 seconds, then lift the gauge. The screen should display 0.0, and the gauge will return to the main interface.
- Zero-point calibration is complete.
Figure 3: Zero-point calibration on an uncoated metal matrix.
4.2.2. Two-Point Calibration
- Stack a standard coating thickness sheet (e.g., 500µm) on an uncoated metal matrix.
- Place the gauge vertically on the stacked sheets.
- Hold for 2 seconds, then lift the gauge. The measured value will be displayed.
- Use the Value plus/minus buttons to adjust the displayed value to match the thickness of the standard sheet.
- Press OK/Menu to confirm the calibration.
- Place the gauge vertically on the uncoated matrix.
- Hold for 2 seconds, then lift the gauge. The screen should display 0.0, and the gauge will return to the main interface.
- Two-point calibration is complete.
Figure 4: Two-point calibration using a standard thickness sheet.
4.2.3. Calibration Verification
After calibration, measure the thickness of a standard coating thickness sheet. The measured value should fall within the specified error range of the nominal value. If not, recalibration is needed.
5. Operating Instructions
5.1. General Measurement
- Ensure the probe is clean and free from obstructions.
- Place the probe vertically on the object to be measured, ensuring close contact with the surface.
- The displayed value is the estimated coating thickness.
- For accurate results, take 3 to 5 measurements at different points on the surface and calculate the average.
Figure 5: Measuring car paint thickness with UT343D.
5.2. Menu Navigation
From the main interface, short press the OK/Menu button to access the menu. Use the Up/Down buttons to navigate and OK/Menu to select.
5.2.1. Length Unit
Select the 'µm/mil' icon to switch between micrometers (µm) and mils (mil).
5.2.2. Probe Mode
Select the 'Mode' icon to choose between 'Automatic', 'Fe' (ferrous), or 'NFe' (non-ferrous) modes. In 'Automatic' mode, the gauge identifies the matrix type automatically.5.2.3. Data Storage Location
Select the 'Group' icon to choose a storage group (1-55). Each group can store up to 60 data sets. The UT343D has a high-capacity memory chip that can store 500 sets of data.
Figure 6: Mass storage chip for data.
5.2.4. Continuous Measurement
Select the continuous measurement icon to enable/disable continuous measurement mode. In this mode, the product will continuously measure until turned off.
5.2.5. Upper/Lower Limit & LED Alarm
Set upper and lower limits for measurements. The gauge features a 3-color LED warning light:
- Red LED: Measurement is lower than the lower limit.
- Green LED: Measurement is between the lower and upper limits.
- Yellow LED: Measurement is higher than the upper limit.
Figure 7: 3-color warning light in action.
5.2.6. Voice Broadcast, Buzzer, Language, Backlight Brightness, Bluetooth
These settings allow customization of audio prompts, alarm sounds, display language (English/Chinese), screen brightness (5 levels), and Bluetooth connectivity. If Bluetooth is enabled but not connected for 5 minutes, it will automatically turn off.
5.3. Quick Test Mode
The quick test mode is ideal for automotive and industrial product coating thickness measurements. Long press the OK/Menu button to enter this mode.
5.3.1. Single Point Quick Test
- Set the target thickness value and tolerance using the Up/Down buttons.
- Measure the coating thickness of the object.
- The screen will display the measured value and a 'PASS' or 'FAIL' result.
Figure 8: Single point quick judgment mode.
5.3.2. Multi-Point Quick Test
- Set the target thickness value and tolerance.
- Measure the coating thickness at 3-5 points on the object. For each point, take 3 measurements, and the gauge will calculate the average for that point.
- After all points are measured, the screen displays the average value of all points and a 'PASS' or 'FAIL' result.
Figure 9: Multi-point quick judgment mode.
6. Maintenance
6.1. Cleaning
Clean the gauge casing with a soft cloth and mild detergent. Do not use abrasive cleaners or solvents, as they can damage the device. Keep the sensor clean and free from dust, oil, and other contaminants.6.2. Battery
The UT343D is powered by a 3.7V 1300mAh rechargeable lithium battery. When the low battery symbol appears on the LCD, charge the product promptly using the original USB cable and a 5VDC 1A power adapter.
7. Troubleshooting
7.1. Inaccurate Readings
If measurements are inaccurate, ensure the sensor is clean and undamaged. Perform a two-point calibration as described in section 4.2.2. If issues persist, consider restoring factory settings.7.2. Low Battery Indication
If the low battery symbol appears, charge the device immediately. The low battery indication triggers at 3.4V ± 0.2V.7.3. Gauge Unresponsive
If the gauge does not respond, check the battery level. If the measured value exceeds 2200µm, the gauge may not respond.
7.4. Restore Factory Settings
If experiencing persistent issues or incorrect calibration, navigate to the menu and select the 'Restore factory settings' option. This will reset all settings to their default values.
8. Specifications
8.1. Technical Indexes
| Function | Range | Thickness | Resolution | Accuracy | Description |
|---|---|---|---|---|---|
| Ferrous and non-ferrous matrixes measurement (Fe and NFe) | 0~2000µm | 0~99.9µm | 0.1µm | ±(2%H+2)µm | 1mil=25.4µm |
| 100~2000µm | 1µm | ||||
| 0~78.7mil | 0~4.99mil | 0.01mil | ±(2%H+0.08)mil | ||
| 5.0~78.7mil | 0.1mil | ||||
| Bluetooth APP | System requirements | ||||
| Searching time | 5min | If no connection for 5 minutes, the Bluetooth function will be automatically turned off. | |||
| Transmission distance | ≥10m | ||||
| Probe measuring force | 0.3~1.5N | Probe measuring force range | |||
| Display | Color display | 2" color TFT screen | |||
| Auto rotatable screen | According to the built-in gravity sensor | 4 directions: 0°, 90°, 180° and 270° | |||
| Unit conversion | µm/mil | Metric/imperial unit conversion | |||
| LED alarm | The LED lights up in the corresponding color when the value exceeds the set range for alarm. | ||||
8.2. General Specifications
| Feature | Specification |
|---|---|
| Display | 2” color TFT screen |
| Refresh rate | 0.5s |
| Sensor type | Large range composite sensor |
| Impact resistance | Can withstand 1 meter drop |
| Power | 5VDC 1A power adapter (USB interface) |
| Product size | 152 × 65 × 35mm |
| Weight | About 180g (including battery) |
| Battery | 3.7V 1300mAh lithium battery |
| Operating environment | 0~40°C, ≤80%RH |
| Storage environment | -20~60°C, ≤75%RH |
8.3. Model Comparison (UT343A, UT343D, UT343E)
| Feature | UT343A | UT343D | UT343E |
|---|---|---|---|
| Iron matrix measuring range | 0~1750µm | 0~1250µm | 0~2000µm |
| Non-ferrous substrate measuring range | 0~68.9mil | 0~49.2mil | 0~78.7mil |
| Minimum convex curvature radius | 5mm | 5mm | |
| Minimum concave curvature radius | 50mm | 50mm | |
| Minimum measured area diameter | 20mm | 20mm | |
| Minimum basic thickness | 0.5mm | 0.5mm | |
| Display screen | EBTN color display | 2" TFT LCD display | |
| Automatic screen rotation | Manually rotate the screen display content | Automatically rotate the screen display content | Yes |
| Unit conversion | √ | √ | um/mil |
| Alarm indication | √ | √ | LED / Audio alarm: YES |
| Voice prompt | √ | √ | Voice broadcast: YES |
| Limit setting | 0~1750µm | 0~1250µm | |
| Measurement method | Single/continuous | Single/continuous | Single/Continuous |
| Statistical measurement | maximum value/minimum value/average value | maximum value/minimum value/average value | Avg, Sdev, Max, Min |
| Automatic recognition | √ | √ | Probe automatically recognizes the substrate |
| USB communication | Product data storage and analysis via USB link computer software | ||
| Data storage | 199 groups | 500 groups | 3300 data |
| Backlight brightness | adjustable | ||
| Automatic shut-down | 5 minutes automatic shutdown | ||
| Low battery prompt | 2.2V±0.2V prompts low battery symbol flashes | ||
| Size | 117*53*37mm | 152*65*35mm | |
| Weight | 111g | 180g | |
| Bluetooth App function | NO | NO | YES |
| Flashlight | NO | NO | YES |
9. User Tips
- Model Selection: The UT343D is one of several variants (UT343A, UT343E). Ensure you have the correct model for your specific needs, as features like Bluetooth connectivity, measurement range, and data storage capacity vary between models. Refer to the model comparison table in the specifications section.
- Calibration Importance: Always perform calibration, especially two-point calibration, if the device hasn't been used for a while or if the environment has changed, to ensure measurement accuracy.
- Data Management: Utilize the 500-group data storage and USB communication features to export and analyze your measurement data on a computer.
- Screen Orientation: Take advantage of the automatic screen rotation for easy reading from any angle.
10. Warranty and Support
10.1. Limited Warranty and Liability
Uni-Trend guarantees that this product is free from any defect in material and workmanship for one year from the purchase date. This warranty does not cover damages caused by accident, negligence, misuse, modification, contamination, or improper handling. For warranty service, contact your seller directly. Uni-Trend is not responsible for any special, indirect, incidental, or subsequent damage or loss.
10.2. User Manual (PDF)
A comprehensive user manual in PDF format is available for detailed instructions and troubleshooting. You can view the PDF manual here.
