UNI-T UT320T 2-in-1 Thermometer User Manual
Comprehensive user manual for the UNI-T UT320T 2-in-1 Thermometer, covering operation, safety precautions, specifications, maintenance, and troubleshooting for infrared and probe temperature measurements.
Foreword
Thank you for purchasing this brand-new UNI-T product. To ensure you can use this product safely and correctly, please read this manual carefully, especially the safety precautions.
It is recommended to keep the manual in an easily accessible place, preferably near the device, for future reference after reading.
Limited Warranty and Liability
UNI-T warrants the product to be free from material and workmanship defects within one year of the purchase date. This warranty does not apply to damage caused by accident, negligence, misuse, alteration, contamination, or improper handling. The dealer is not authorized to give any other warranty on behalf of UNI-T. If you require warranty service within the warranty period, please contact your seller directly.
This warranty is the sole compensation you can receive. UNI-T shall not be liable for special, indirect, incidental, or consequential losses or damages caused by any reason or speculation. As some areas or countries do not allow limitations on implied warranties and incidental or consequential damages, the above limitation of liability and provision may not apply to you.
About
Due to different batches, the materials and details of the actual products may differ slightly from the graphic information. Please refer to the goods received. The experimental data in the manual are theoretical values, all from UNI-T's internal laboratories and are for reference only. Customers cannot use them as a basis for orders. For any questions, please contact customer service.
Safety Precautions
⚠️ Warning: To prevent eye or personal injury, please read the following safety precautions before using the product:
- Do not point the laser directly at people or animals, or indirectly through reflective surfaces.
- Do not look directly into the laser or through optical aids (binoculars, microscopes, etc.).
? LASER RADIATION, DO NOT STARE INTO BEAM, CLASS 2 LASER PRODUCT
Compliance with IEC/EN 60825-1, EN 50689.
When the probe is extended, do not point it at people or animals.
Precautions:
- If the laser beam hits the user's eyes, close them immediately and turn your head away.
- Do not disassemble or reconstruct the product and laser without authorization.
- To ensure its safety and accuracy, this product should only be repaired by professional maintenance personnel using original replacement parts.
- Replace the batteries when the battery indicator shows, to avoid incorrect measurements.
- Please inspect the product before use. If it is damaged, has cracks on the surface, or is missing plastic parts, do not use it.
- In infrared measurement mode, highly reflective objects or transparent materials may cause the actual temperature to be higher than the measured temperature. Be aware of the risk of burns when measuring such objects.
- Do not use the product in an environment with flammable and explosive liquids, gases, or dusts.
- Do not use the product in an environment with steam, dust, or large temperature fluctuations when in infrared measurement mode. This may lead to inaccurate results and risks.
- Place the product in the current environment for more than 30 minutes before use to ensure the accuracy of infrared measurement.
- Do not leave the thermometer on or near high-temperature objects.
- Do not let the plastic housing come into contact with high-temperature objects to prevent deformation and melting of the plastic.
- Do not insert the probe into the measurement object for a long time in probe mode. Remove the probe after 1 minute of measurement and then measure after the product has returned to normal temperature.
- Do not place the product in a dishwasher, oven, microwave, or soak it in any liquid.
Product Structure
The UT320T thermometer has the following components:
- 1. Infrared Sensor
- 2. Single Laser
- 3. LCD Display
- 4. Scan/Hold Button: Press to turn on the thermometer in infrared mode or wake it up in probe mode. In infrared mode: Press to measure, release to save data. In probe mode: Switch measurement state (automatic measurement/hold).
- 5. Max/Min | ε Button: Short press (less than 0.5 seconds): Display Maximum or Minimum value. Long press (approx. 1.5 seconds): Activate emissivity setting function.
- 6. T1/T2 | °C/°F Button: Short press (less than 0.5 seconds): Activate T1/T2 temperature difference calculation function. Long press (approx. 1.5 seconds): Convert temperature units (°C/°F).
- 7. Probe
- 8. Probe Dial
- 9. Battery Cover Screw
Display Indicators/Symbols
The LCD screen displays various indicators:
- H: Data Hold
- Lock Measurement: Lock Measurement
- ε: Emissivity
- Value Display: Displays the measured temperature.
- T1-T2: Temperature Difference
- MAX/MIN: Infrared/Probe Measurement (Indicates whether Max/Min mode is active)
- Low Battery: Indicates low battery
- Temperature Units (°F/°C): Displays the selected temperature unit.
- Maximum/Minimum Temperature: Displays the maximum or minimum recorded temperature.
Performance Specifications
| Model | UT320T | Probe Type | NTC |
|---|---|---|---|
| LCD Size | 18*28mm | Probe Measurement Minimum Depth of Insertion | 12.7mm |
| LCD Type | FSTN | Operating Duration | Approx. 180 hours (backlight on) |
| Measurement Range | -40°C~300°C (-40°F~572°F) | Over-range/Under-range Display | Measured Value > Max Range: Display "OL". Measured Value < Min Range: Display "-OL". |
| Range | Accuracy | Operating Temperature | 0°C~50°C (32°F~122°F) |
| -40°C ≤ t ≤ 0°C: | ±(2.0+0.1×|t|)°C | Storage Temperature | -20°C~60°C (-4°F~140°F) |
| 0°C < t ≤ 300°C: | ±2.0 °C or ±0.02xt °C, whichever is greater | Operating Humidity | <90%RH (non-condensing) |
| -40°F ≤ t ≤ 32°F: | ±(4.0+0.1×|t-32|)°F | Highest Operating Altitude | 2000m |
| 32°F < t ≤ 572°F: | ±4.0 °C or ±0.02xt °C, whichever is greater | IP Rating | IP54 |
| Temperature Coefficient | ±0.1 °C/°C or ±0.1%/°C, whichever is greater | Drop Test | 2m Guaranteed Precision |
| Measurement Distance to Spot Ratio (D:S) | 8:1 | Battery Type | 2* 1.5V AAA |
| Emissivity | Adjustable (0.1~1.0) | Auto Power Off Time | 10min |
| Spectral Range | 5μm~14µm | Data Hold | √ |
| Response Time | ≤500ms (95% of reading) | Lock Measurement | √ |
| Repeatability | ±1.0°C or ±1.0% whichever is greater (±2.0°F or 1.0%, whichever is greater) | Unit Conversion (°C/°F) | √ |
| Laser | Class 2, Single Laser, Power <1mW, Wavelength 650±20nm | Max/Min/Difference | √ |
| Operating Duration | Approx. 30 hours (Laser and backlight on) | Infrared- | √ |
| Probe Measurement Range | -40°C~300°C (-40°F~572°F) | ||
| Probe Measurement Accuracy | -40°C ≤ t < 0°C: ±2.0 °C or ±0.01xt °C, whichever is greater 0°C < t ≤ 300°C: ±1.0 °C or ±0.01xt °C, whichever is greater -40°F ≤ t ≤ 32°F: ±4.0°F 32°F < t ≤ 572°F: ±2.0°C | ||
| Certifications |
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| Product Weight | Approx. 110 hours (with batteries) | ||
| Product Size | 155*42*22.5mm |
Operation
6.1 Battery Replacement
When you use the UT320T thermometer for the first time, please insert the batteries first.
How to remove the battery cover:
- Hold the metal ring with one hand or a tool on the screw and turn the ring counterclockwise to unscrew the battery cover screw.
- Unscrew the battery cover screw with a screwdriver.
Battery Type:
- 2 AAA Alkaline Batteries
Note:
- Pay attention to the battery polarity during installation.
- After replacing the batteries, close the battery cover and tighten the screw.
6.2 Power On/Off
- When the probe is folded, press the Scan/Hold button to turn on the thermometer and switch to infrared mode (non-contact).
- When the probe is extended, it switches to probe mode (contact mode), and the thermometer will turn off when the probe is folded (not in T1/T2 mode).
- When the thermometer is turned on, the backlight will automatically turn off if no button is pressed for nine minutes, and the product will automatically shut down if no button is pressed for one minute.
- When the probe is extended, after the product has automatically shut down, press the Scan/Hold button to wake it up.
- In T1/T2 mode, the temperature difference can be calculated. When the probe is extended in T1/T2 mode, fold the probe to switch to infrared mode, and the thermometer will not shut down. If users want to fold the probe to turn off the thermometer, please exit the T1/T2 mode first.
6.3 Temperature Measurement
Infrared Mode:
- Press the Scan/Hold button to measure the temperature, and release it to end the measurement. The symbol will be displayed in the upper left corner of the LCD, and the data will be saved.
Probe Mode:
- When the probe is extended, the product starts measuring automatically. Insert the probe at least 12.7 mm into the object to be measured and wait for the value to stabilize before reading the temperature. Press the Scan/Hold button. The symbol will be displayed in the upper left corner of the LCD, and the data will be saved. Press the Scan/Hold button again to return to automatic measurement.
6.4 Function Settings
Lock Measurement in Infrared Mode:
- When the measurement data is held in infrared mode, press the Scan/Hold button twice; the symbol will be displayed in the upper right corner of the LCD, and the thermometer will switch to lock measurement mode. Measurement can be performed at this time without pressing a button.
- When Scan/Hold is pressed in the locked measurement state, the symbol in the upper right corner of the LCD will disappear, ending the locked measurement.
Max/Min:
- When the measured data is held, press the Max/Min button. Press the ε button to cycle through Max, Min (last continuous measurement), and the display of Max/Min.
- When the temperature is measured with the Max/Min function activated, Max and Min of the current continuous measurement will be displayed.
Emissivity Adjustment:
- Long press the Max/Min button. Press the ε button to enter the emissivity adjustment interface.
- In the adjustment interface, press the Up/Down buttons to adjust the value. Press and hold to add or subtract 0.1 per second.
- After the emissivity is set, press the Scan/Hold button to save the emissivity and return to the measurement interface.
- This function can only be activated in infrared mode.
Temperature Difference:
- After the thermometer is turned on for measurement, briefly press the T1/T2 button. Press the °C/°F button to cycle through T1>T2>T1-T2>T1. When T1-T2 is displayed, press the Scan/Hold button to exit T1/T2 mode (or long press the T1/T2 button. Press the °C/°F button to exit in any state of T1/T2 mode).
Temperature Units:
- Long press the T1/T2 button. Press the °C/°F button to cycle through temperature units °C/°F.
Infrared Measurement
7.1 D:S (Distance to Spot Ratio)
As the distance (D) between the thermometer and the object to be measured increases, the spot diameter (S) of the measured area also increases. The relationship between measurement distance and spot diameter is shown in the following figure.
Spot Diameter (S):
- 0.5" (13 mm)
- 1" (25 mm)
- 2" (51 mm)
- 4" (102 mm)
Distance to Measured Target (D):
- 4" (102 mm)
- 8" (203 mm)
- 16" (406 mm)
- 32" (813 mm)
The spot diameter represents 95% of the energy.
7.2 Field of View
When measuring, ensure that the object to be measured is larger than the spot diameter (S). The smaller the target, the closer the test distance should be (see D:S for detailed spot diameter). It is recommended that the object to be measured is larger than twice the spot diameter of the thermometer.
7.3 Emissivity
Emissivity represents the ability of the object to emit infrared energy. Infrared measurement is used to measure infrared energy to determine temperature.
Objects made of different materials have different emissivity. The emissivity of most organic materials, painted or oxidized surfaces is about 0.95. The user can use masking tape or flat colors to cover the metal surface, and then wait for a period of time for the surface temperatures of the masking tape/flat colors and the covered object to equalize. At this time, the surface temperature of the masking tape/flat colors is the same as the surface temperature of the metal.
The following table shows the total emissivity of some metals and non-metals.
| Measured Surface | Emissivity | ||
|---|---|---|---|
| Metals | |||
| Aluminium | 0.2-0.4 | ||
| Oxid | 0.3 | ||
| A3003Alloy | 0.1-0.3 | ||
| Roh | 0.3 | ||
| Blech | 0.3 | ||
| Polieren | 0.5 | ||
| Cuprum | 0.4-0.8 | ||
| Oxid | 0.5 | ||
| Elektrische Klemmleiste | 0.6 | ||
| Hastelloy Legierung | 0.6 | ||
| Inconel | 0.7-0.95 | ||
| Oxid | 0.3-0.8 | ||
| Strahlmittel | 0.15 | ||
| Elektropolieren | 0.5 | ||
| Plumbum | 0.2-0.6 | ||
| Roh | 0.2-0.6 | ||
| Oxid | 0.2-0.5 | ||
| Molybdän | 0.2-0.6 | ||
| Oxid | 0.2-0.5 | ||
| Nickel | 0.2-0.5 | ||
| Oxid | 0.2-0.5 | ||
| Ferrum | 0.5-0.9 | ||
| Oxid | 0.5-0.7 | ||
| Rostend | 0.5-0.7 | ||
| Ferrum (Gießen) | 0.6-0.95 | ||
| Oxid | 0.2 | ||
| Nicht-Oxid | 0.2-0.3 | ||
| Guss | 0.2-0.3 | ||
| Ferrum (Schmieden) | 0.9 | ||
| Passivierung | 0.4 | ||
| Platin | 0.2-0.6 | ||
| Schwarz | 0.9 | ||
| Non-metals | |||
| Stahl | 0.7-0.9 | ||
| Kaltwalzen | 0.4-0.6 | ||
| Brünieren | 0.4-0.6 | ||
| Polieren | 0.1 | ||
| Zink | 0.1 | ||
| Oxid | 0.1 | ||
| Non-metals | |||
| Asbest | 0.95 | ||
| Asphalt | 0.95 | ||
| Basalt | 0.7 | ||
| Kohlenstoff | |||
| Nicht-Oxid | 0.8-0.9 | ||
| Graphit | 0.7-0.8 | ||
| Carborundum | 0.9 | ||
| Keramik | 0.95 | ||
| Ton | 0.95 | ||
| Beton | 0.95 | ||
| Stoff | 0.9 | ||
| Glas | |||
| Konvexes Glas | 0.76-0.8 | ||
| Glattes Glas | 0.92-0.94 | ||
| Nonex | 0.78-0.82 | ||
| Plattenmaterial | 0.96 | ||
| Kalkstein | 0.8-0.95 | ||
| Gips | 0.98 | ||
| Eis | 0.98 | ||
| Plastik | 0.95 | ||
| Wasser | 0.95 | ||
| Boden | 0.93 | ||
| Holz | 0.9-0.98 | ||
Maintenance and Cleaning
The IP rating of the UT320T thermometer is IP54. The housing and probe can be cleaned with a damp sponge or a soft cloth. Please dry the product after cleaning.
Use a cotton swab soaked in water or medical alcohol to clean the surface of the lens. Ensure the lens surface is dry before proceeding.
Troubleshooting
| Phenomenon | Cause | Measure |
|---|---|---|
| "OL" Display | Measured Value > Maximum Range | Stop Measurement |
| "-OL" Display | Measured Value < Minimum Range | Stop Measurement |
| Display Error (Initialization) | Exceeding minimum/maximum operating temperature or damage to the infrared sensor | Place the thermometer at 0°C to 50°C (32°F-122°F) for 30 minutes. If Err is still displayed, the product needs to be repaired. |
| Battery Symbol Blinks | Low Battery | Replace Batteries |
| Display Error (Initialization) | Internal Damage | Restart the product, or reinsert the batteries and then restart it. If the product still does not function normally, repair it. |
| Inaccurate Infrared Measurement | Measurement distance too large, object diameter < 12mm | Refer to Field of View, D:S, and other instructions in this manual for more information. |
| Inaccurate Probe Measurement | Probe damage, insert the probe less than 12.7 mm into the object. | Repair the probe if it is damaged. |
Usage Notes
Infrared Measurement:
- Do not place the device in an environment with sudden changes in room temperature. If the ambient temperature changes (e.g., from indoors to outdoors), the thermometer should wait at least 30 minutes to stabilize. If the thermometer does not reach the required temperature conditions, it may lead to errors.
- Please check if the infrared sensor lens is clean. If there is dust and foreign matter on the lens, clean the lens according to the maintenance and cleaning method and continue measuring after the lens surface is dry.
- Ensure there are no other obstructions between the product and the object being measured.
Probe Measurement:
- The probe has a minimum insertion depth of 12.7 mm.
- Do not use the product in corrosive acids or alkalis.
