UNI-T UT306C Infrared Thermometer User Manual

Overview

The UT306C infrared thermometer is designed for quick and accurate non-contact surface temperature measurements by detecting infrared energy radiated by the target. It features a Distance to Spot (D:S) ratio of 12:1.

Safety Instructions

▲ Warning:

To prevent eye damage or personal injury, adhere to the following safety guidelines:

• Do not point the laser directly at people or animals, or indirectly through reflective surfaces.
• Avoid looking directly at the laser, even with optical tools like binoculars or microscopes.

A LASER
CLASS 2 LASER PRODUCT
λ=630-670nm, <1mW

Cautions:

• If the laser beam affects your eyes, close them immediately and turn your head away.
• Do not disassemble or modify the product or laser without authorization. Repairs should only be performed by qualified personnel using original parts.
• Replace batteries when the low battery indicator appears to ensure accurate measurements.
• Inspect the product for damage (cracks, missing parts) before use. Do not use if damaged.
• Refer to emissivity information for accurate temperature readings. Highly reflective or transparent objects may yield higher measured temperatures than actual, posing a burn risk.
• Avoid using the product in environments with flammable or explosive liquids, gases, or dust.
• Do not use in environments with steam, dust, or significant temperature fluctuations, as this can lead to inaccurate results and risks.
• Allow the thermometer to acclimatize to the current environment for at least 30 minutes before use for optimal accuracy.
• Do not leave the thermometer on or near high-temperature objects.

Technical Indexes

Characteristics

• Features a ring laser for more accurate measurement indication.
• Equipped with a bright, high-contrast color EBTN display for easy readability.
• Supports MAX/MIN/AVG/DIF data hold functions.
• Includes a buzzer sound alarm for quick anomaly detection.
• Offers trigger lock functionality for continuous temperature monitoring.
• Short press the `[LASER]` button in shutdown mode to take a measurement.

Appearance

The thermometer consists of the following parts:

• 1: Laser
• 2: Infrared receiving window
• 3: Trigger
• 4: Battery door
• 5: LCD display
• 6: LOCK button
• 7: MODE button
• 8: LASER button
• 9: Laser warning label

LCD Indicators

The LCD display shows various indicators:

• [HOLD]: Indicates data is being held.
• [SCAN]: Flashes when actively scanning temperature.
• [MAX]: Displays the maximum measured temperature.
• [MIN]: Displays the minimum measured temperature.
• [AVG]: Displays the average measured temperature.
• [DIF]: Displays the difference between the last two measurements.
• [HI]: Indicates the measured temperature exceeds the high alarm limit.
• [LO]: Indicates the measured temperature is below the low alarm limit.
• [LASER]: Indicates the laser pointer is active.
• [BATTERY]: Indicates low battery status.
• [°C/°F]: Indicates the selected temperature unit.

Operating Instructions

Startup

Short press (less than 0.5s) the trigger to power on the thermometer. The last measured value before shutdown will be displayed. Pressing the MODE button allows cycling through MAX/MIN/AVG/DIF modes.

Shutdown

The thermometer automatically shuts down after 15 seconds of inactivity in HOLD mode, saving the current measurement.

Manual Measurement

1. Aim the thermometer at the target.
2. Press and hold the trigger. The [SCAN] symbol will flash, indicating measurement is in progress. The LCD updates with the result.
3. Release the trigger. The [SCAN] symbol disappears, and the [HOLD] symbol appears, freezing the last measured value.

Lock Measurement

1. Short press the LOCK button to enter lock measurement mode. The [LOCK] symbol appears, and the [SCAN] symbol flashes. The thermometer continuously measures temperature without needing to hold the trigger.
2. Press the trigger or short press the LOCK button again to exit lock mode. The [LOCK] and [SCAN] symbols disappear, and the [HOLD] symbol appears, freezing the last measurement.
3. Short pressing the LOCK button while the device is off wakes it up and enters lock measurement mode.
4. Pressing and holding the LOCK button for over 3 seconds is considered a misoperation.

MAX/MIN/AVG/DIF Value

Short press the "MODE" button to cycle through MAX, MIN, AVG, and DIF measurement modes. The corresponding temperature value is displayed in the secondary display area.

Example displays:

• MAX: Displays the highest temperature recorded.
• MIN: Displays the lowest temperature recorded.
• AVG: Displays the average temperature recorded.
• DIF: Displays the difference between the highest and lowest temperatures recorded.

Laser Indicator

Pressing the `[LASER]` button toggles the laser pointer on/off. When active, the [LASER] symbol appears on the LCD, indicating the measurement spot. Always follow safety cautions to avoid eye injury.

High and Low Temperature Alarm

• If the measured temperature exceeds the set high alarm limit, the [HI] symbol flashes, and the buzzer sounds (if enabled).
• If the measured temperature falls below the set low alarm limit, the [LO] symbol flashes, and the buzzer sounds (if enabled).
• When the temperature is within the set alarm limits, neither [HI] nor [LO] symbols are displayed.

Function Settings

From the [HOLD] interface, long press the "MODE" button (over 2 seconds) to access settings for High Alarm Limit, Low Alarm Limit, Emissivity, Temperature Unit, and Sound Alarm. Pressing the trigger or no operation for 10 seconds returns to the [HOLD] interface.

High Alarm Limit Setting

In the [HOLD] interface, long press "MODE" to enter the high alarm limit setting. Use `[up-arrow]` or `[down-arrow]` buttons to adjust. Short presses increment/decrement by 1; long presses increment/decrement by 10 per second.

Low Alarm Limit Setting

In the [HOLD] interface, long press "MODE" then short press "MODE" once to enter the low alarm limit setting. Adjust using `[up-arrow]` or `[down-arrow]` buttons.

Emissivity Setting

In the [HOLD] interface, long press "MODE" then short press "MODE" twice to enter the emissivity setting. Adjust using `[up-arrow]` or `[down-arrow]` buttons. Short presses change by 0.01; long presses change by 0.1 per second.

Temperature Unit Setting

In the [HOLD] interface, long press "MODE" then short press "MODE" three times to enter the temperature unit setting. Use `[up-arrow]` or `[down-arrow]` to switch between °C and °F.

Sound Alarm Setting

In the [HOLD] interface, long press "MODE" then short press "MODE" four times to enter the sound alarm setting. Use `[up-arrow]` or `[down-arrow]` to enable or disable the sound alarm.

Field of View and D:S Ratio

The Distance to Spot (D:S) ratio indicates the relationship between the measurement distance (D) and the diameter of the measurement spot (S). As the distance increases, the spot size also increases. For accurate measurements, the target's size should be larger than the spot diameter. It is recommended that the target be at least twice the spot diameter.

Example: For an object approximately 4 inches (10cm) in diameter, the UT306C's spot diameter is about 2 inches (5cm) at a distance of 24 inches (60cm) (based on D:S = 12:1).

D: S (Distance to Spot Ratio) Diagram Description: The diagram illustrates how the spot size (S) increases with distance (D). It shows three scenarios: 'Bad' (target smaller than spot), 'So-So' (target size comparable to spot), and 'Good' (target significantly larger than spot). The text clarifies that the spot diameter represents 95% of the energy within the circle.

Spot Size @ Distance D:S = 12:1:

• 1 inch @ 12 inches
• 2 inches @ 24 inches
• 4 inches @ 48 inches
• 50mm @ 600mm
• 100mm @ 1200mm

Emissivity: Emissivity (ɛ) is a measure of a material's ability to radiate thermal energy. Most organic materials and painted/oxidized surfaces have an emissivity of around 0.95. For reflective or difficult surfaces, masking tape or flat paint can be used to create a more emissive surface. The table below provides emissivity values for various materials.

Maintenance

Cleaning

Use clean compressed air to blow away loose particles. Gently wipe the lens surface with a moist swab. Clean the shell with a moist sponge or soft cloth. Do not rinse with water or immerse the device in water.

Replace Batteries

Install or replace the two 1.5V batteries following these steps:

1. Remove the battery door.
2. Install batteries, observing correct polarity.
3. Close the battery door.

Troubleshooting