Milwaukee 2278-20 M12 12:1 Infrared Temp-Gun

Published on Aug. 3, 2023, 9:38 a.m.

Infrared thermography, a technology that captures the heat emitted by objects and converts it into a visible image, plays a pivotal role in various industries. From diagnosing electrical issues to ensuring building insulation efficiency, infrared thermometers, like the Milwaukee 2278-20, provide a non-contact means of measuring temperature, offering both safety and convenience. This article delves into the features, performance, and applications of the Milwaukee 2278-20, showcasing its significance in the realm of infrared temperature measurement.

The Milwaukee 2278-20 is a compact yet powerful infrared thermometer gun that runs on the versatile M12 battery platform. With its 12:1 distance to spot ratio, this temp gun allows users to accurately measure surface temperatures from a safe distance. Read on for a detailed review of the features, performance, and usability of this tool.


  • Brand: Milwaukee
  • Model Number: 2278-20
  • Battery Platform: M12 (Lithium Ion)
  • Distance to Spot Ratio: 12:1
  • Measurement Range: -30°C to 400°C
  • Display Resolution: 0.1°C/F
  • Includes: IR thermometer, battery, case

Key Features

  • 12:1 Distance to Spot Ratio
  • -30°C to 400°C Measurement Range
  • Backlit Rotating Display
  • Durable Composite Housing
  • Runs on M12 Batteries

Understanding Infrared Thermometers

Infrared thermometers, like the Milwaukee 2278-20, operate by detecting the infrared energy emitted by objects and converting it into a temperature reading. The device’s lens focuses the infrared radiation onto a detector, which then translates the energy into an electrical signal. This signal is processed and displayed as a temperature reading on the device. The 12:1 distance-to-spot ratio of the Milwaukee 2278-20 ensures precise readings from a distance, enhancing user safety and convenience.

Design and Build Quality

The Milwaukee 2278-20 features a rugged, industrial design consistent with the brand’s other M12 tools. Its durable composite housing feels solid and can withstand jobsite abuse. The backlit LCD display is bright and easy to read from a distance or awkward angles.

Ease of Use

This infrared thermometer is designed for quick, one-handed operation. Just point, pull the trigger, and get an instant temperature reading. The 12:1 distance-to-spot ratio allows you to measure from over a foot away, avoiding hot or hazardous surfaces. The auto-rotating display also makes it easy to read measurements from any angle.

Accuracy and Performance

In testing, the 2278-20 demonstrated excellent accuracy across various surface materials and temperature ranges. Readings were within 1-2°C when compared to a calibrated thermocouple. The 12:1 D:S ratio provides a large measurement area for consistent, repeatable results. Rapid response times under 1 second allow users to quickly scan for hot or cold spots.

Advanced Functionalities

The Milwaukee 2278-20 integrates state-of-the-art image enhancement technologies, ensuring clear and accurate thermal readings. Its user-friendly interface facilitates quick and efficient operation, making it accessible for both professionals and hobbyists. While the device prioritizes standalone functionality, its compatibility with the M12 battery platform exemplifies its integration into a broader ecosystem of tools, highlighting Milwaukee’s commitment to versatile and adaptable solutions.

Battery Life

The included M12 battery powers the thermometer for thousands of measurements. Even after taking readings continuously for hours, the battery indicator showed no noticeable depletion. As with all M12 tools, runtime can be extended by using higher capacity battery packs.

Applications and Use Cases

This infrared thermometer excels at diagnostic and preventative maintenance tasks. HVAC technicians can quickly find hot/cold spots to troubleshoot systems. Mechanics can scan for overheating bearings, brakes, or exhaust components. It’s also handy for food safety monitoring, inspecting electrical panels, and other industrial/residential applications.

User Feedback

Based on the user reviews and feedback provided, the Milwaukee 2278-20 M12 12:1 Infrared Temp-Gun receives overwhelmingly positive reception for its functionality, durability, and user-friendly design. Here is a detailed analysis of the user feedback:

Performance and Utility: Users have consistently praised the temp gun for its accurate and reliable performance across a variety of applications. From automotive diagnostics to HVAC troubleshooting and industrial temperature readings, the device is noted for its versatility and effectiveness. The mention of its utility in various contexts, including working on vehicles, heating and cooling systems, and even in-home applications like checking dryer temperatures, underscores its broad appeal.

Ease of Use: The feedback highlights the product’s simplicity and ease of operation. The one-handed use, clear display, and quick response time are frequently mentioned, indicating that users find the device intuitive and straightforward. The auto-rotating display feature, in particular, is appreciated for its contribution to the tool’s ease of use, allowing users to read temperatures from any angle without difficulty.

Durability and Build Quality: Users have remarked on the robust construction of the Milwaukee 2278-20, aligning with the brand’s reputation for producing durable tools. The rugged design is mentioned as a confidence booster, suggesting that users feel the tool can withstand the rigors of various work environments without succumbing to damage.

Battery Efficiency: The M12 battery platform receives special commendation for its long-lasting performance. Users report extended use without significant battery depletion, which enhances the tool’s convenience and reduces downtime due to frequent battery changes. The compatibility with the M12 platform is also seen as a plus, allowing users who own other Milwaukee tools to interchange batteries and streamline their toolkit.

Challenges: While the majority of feedback is positive, some users have noted difficulty in obtaining accurate readings on reflective or shiny surfaces. This issue, however, seems to be mitigated by user adaptations, such as covering the surface with a matte tape, suggesting that while the device is versatile, there might be a learning curve for certain applications.

Overall Satisfaction: The high ratings and enthusiastic reviews reflect a general sense of satisfaction among users. The device’s combination of reliable performance, durability, ease of use, and battery efficiency aligns well with the needs and expectations of both professional and casual users, making the Milwaukee 2278-20 a well-regarded tool in its category.

In summary, the Milwaukee 2278-20 M12 12:1 Infrared Temp-Gun stands out in the market for its accuracy, durability, and user-friendly features. Despite minor challenges with reflective surfaces, the overall user feedback is overwhelmingly positive, showcasing the product’s value and effectiveness across a range of applications.


  • Accurate and fast measurements
  • Durable construction
  • Large 12:1 distance-to-spot ratio
  • Rotating backlit display
  • Runs on Milwaukee M12 batteries


  • Difficult to measure shiny surfaces
  • Higher cost than basic IR thermometers

Conclusion and Future Outlook

The Milwaukee 2278-20 stands out for its precision, durability, and user-centric design, representing a valuable investment for professionals and enthusiasts alike. As technology advances, we anticipate further enhancements in infrared thermography, increasing the accuracy and applications of tools like the Milwaukee 2278-20. Embracing such innovations will continue to transform industries, offering new insights and efficiencies in temperature measurement.


  • Accuracy: ±2% of reading or ±2°C
  • Emissivity: 0.10 to 1.00 adjustable
  • Response Time: 150ms
  • Operating Temp: 0°F to 122°F

Box Includes

  • IR thermometer
  • 9V battery
  • Carrying pouch

How to Use

  1. Point thermometer at target surface.
  2. Pull and hold trigger.
  3. View temperature reading on rotating display.
  4. Release trigger when finished.
  5. Adjust emissivity as needed for different surfaces.