UNI-T UT309C Infrared Thermometer

Product Description

The UNI-T UT309C Infrared Thermometer is a professional non-contact temperature measurement instrument designed for fast and reliable surface temperature inspection in electrical maintenance, HVAC servicing, industrial equipment, transportation systems, and general troubleshooting applications. By detecting infrared radiation emitted from a target surface, the UT309C allows technicians to measure temperature without physical contact, making it useful for energized, moving, hot, or difficult-to-reach components.

The UT309C provides a wide temperature measurement range of -35°C to 650°C (-31°F to 1202°F) with a resolution of 0.1°C/0.1°F. Its 12:1 distance-to-spot ratio (D) allows users to measure targets from a greater distance while maintaining a defined measurement area. The instrument has a rapid response time of approximately 250ms, making it suitable for quick inspection during maintenance and service operations.

Unlike the UT309A, which uses a fixed emissivity of 0.95, the UT309C provides adjustable emissivity from 0.1 to 1.0. This allows the user to compensate for differences in surface emissivity between materials and improve measurement suitability for a wider range of targets. Its 8–14μm spectral response is optimized for infrared surface-temperature measurement.

The UT309C uses dual Class 2 laser pointers to help identify the approximate measurement area. During inspection, the thermometer provides MAX, MIN, AVG, and DIF modes, allowing users to monitor maximum and minimum temperatures, calculate an average reading, or determine the temperature difference. High- and low-temperature alarms are also provided with LED indication for identifying measurements outside predefined limits.

For field work, the UT309C includes practical functions such as data hold, measurement lock, automatic power-off, low-battery indication, °C/°F selection, and LCD backlight. It also includes a tripod mounting hole for fixed-position measurements. The thermometer is rated IP65 and has passed a 3-meter drop test, providing protection suitable for demanding maintenance environments.

The compact handheld instrument measures approximately 189 × 118 × 55mm and weighs around 292g. It operates from a 9V 6F22 battery, making it convenient for mobile inspection work without requiring an external power source.

With its 650°C measurement capability, adjustable emissivity, 12:1 optical ratio, dual-laser targeting, and rugged IP65 construction, the UNI-T UT309C Infrared Thermometer is well suited to technicians and engineers performing thermal inspections on electrical and mechanical equipment.

Features

• Non-contact infrared temperature measurement

• Wide temperature range from -35°C to 650°C

• 12:1 distance-to-spot ratio

• Adjustable emissivity from 0.1 to 1.0

• Dual Class 2 laser targeting

• Fast 250ms response time

• MAX / MIN / AVG / DIF measurement modes

• High- and low-temperature LED alarms

• Measurement lock and data hold

• °C/°F selection and laser switch

• LCD backlight and low-battery indication

• IP65 protection

• 3m drop resistance

• Tripod mounting hole

Specifications

Specifications are based on UNI-T's official UT309 series documentation.

Applications

• Electrical panel and distribution equipment inspection

• HVAC system maintenance and troubleshooting

• Motors, bearings, pumps, and industrial machinery

• Electrical connection and component temperature inspection

• Industrial equipment preventive maintenance

• Vehicle and transportation equipment inspection

• Mechanical troubleshooting

• Heating and thermal process inspection

• Workshop and field-service temperature measurements

• Inspection of hot or difficult-to-reach surfaces