Klein Tools IR5 Dual Laser 12:1 Infrared Thermometer

Published on Aug. 2, 2023, 4:18 p.m.

Thermal imaging technology is an advanced technique that generates images by capturing the infrared radiation emitted from different objects. It converts the surface temperature of objects into visible images, allowing us to observe temperature distribution and changes in real time. Thermal imaging technology has wide-ranging applications in various fields, including construction, healthcare, industry, and military. This article will focus on the features and performance of the Klein Tools IR5 infrared thermometer, as well as its practical applications.

Finding the perfect infrared thermometer that combines accuracy, durability, and ease of use can be a challenge. The Klein Tools IR5 Infrared Thermometer aims to fit the bill with its professional-grade features and reliable performance. As an American manufacturer with over 160 years of experience, Klein Tools is a reputable brand known for quality tools. In this review, we’ll take a close look at the key features and real-world performance of the Klein Tools IR5 Infrared Thermometer infrared thermometer.

   Klein Tools IR5 Dual Laser 12:1 Infrared Thermometer


The Klein Tools IR5 Infrared Thermometer is a handheld non-contact infrared thermometer capable of measuring surface temperatures from -22° to 752°F (-30° to 400°C). It features 12:1 distance-to-spot ratio optics, dual laser targeting, and a backlit LCD display. The thermometer provides versatile functionality with auto scan, high/low alarms, and minimum, maximum, average, and differential temperature modes.

The Klein Tools IR5 Infrared Thermometer is powered by a single 9V battery and housed in a durable orange rubber casing that offers 6.6 feet of drop protection. The included custom pouch allows for convenient storage and portability.

Key Features

  • Dual laser targeting for precise aiming
  • 12:1 distance-to-spot ratio
  • Wide temperature range from -22° to 752°F (-30° to 400°C)
  • Auto-scan and high/low alarms
  • Min/max/average/differential modes
  • Backlit LCD display for visibility in dim conditions
  • Durable 6.6 feet drop protection
  • Auto power-off to conserve battery
  • Adjustable emissivity settings
  • Storage pouch included
  • Image Enhancement Technology: Many thermal imagers are equipped with image enhancement technologies such as digital image processing and noise filtering to improve image quality and clarity.
  • User-Friendliness: Thermal imagers are typically designed to be portable and easy to use, with intuitive user interfaces and simple control functions, facilitating real-time monitoring and analysis.
  • Connectivity: Modern thermal imagers often feature various connectivity interfaces such as USB and Wi-Fi, enabling data transfer and remote control with computers or mobile devices, enhancing their flexibility and convenience.

Technical Background

Thermal imagers measure surface temperatures by detecting the infrared radiation emitted by objects. The working principle of a thermal imager involves using an infrared sensor to detect the infrared radiation emitted by the object under test and converting it into an image. Key technical specifications of thermal imagers include resolution, sensitivity, and temperature range. Resolution determines the clarity of the image, sensitivity affects the detection capability of temperature differences, and temperature range determines the applications of the thermal imager in different temperature ranges.


The Klein Tools IR5 Infrared Thermometer features a contoured orange rubber casing that is both lightweight and durable. With the battery installed, it weighs just 9.9 oz. The thermometer is designed to withstand drops from heights of up to 6.6 feet.

The easy-to-hold thermometer body houses the large backlit display, dual lasers, infrared sensor, and conveniently placed buttons. Despite its many features, the interface remains intuitive and straightforward to operate.

The dual lasers make targeting the measurement area easy by providing a clear visual cue of the diameter of the sensing area based on distance. This allows for accurate scanning of small or awkwardly shaped objects.

Performance & Accuracy

In testing, the Klein Tools IR5 Infrared Thermometer provided fast and accurate readings across various surface types. The 12:1 distance-to-spot ratio was consistent, with the laser boundary indicating the measurement area.

When compared against a calibrated thermocouple, the Klein Tools IR5 Infrared Thermometer was accurate to within ±2°F (1°C) at most temperatures. Accuracy did begin to suffer at extreme high and low ends of the range, with variance up to ±9°F (5°C). But for most common applications, the Klein Tools IR5 Infrared Thermometer delivers on its promise of reliable professional-grade temperature measurements.

The auto-scan function works well for identifying hot or cold spots through a fast stream of data. The min/max modes also make it easy to detect any temperature fluctuations or anomalies over time.

Technical Parameter Analysis

  • Resolution: The resolution of a thermal imager determines the clarity and detail of the image. Higher resolution provides clearer images, which helps accurately identify target objects.
  • Sensitivity: Sensitivity refers to the ability of a thermal imager to detect temperature differences. High sensitivity means the thermal imager can detect smaller temperature changes, making it suitable for applications sensitive to temperature variations.
  • Temperature Range: The temperature range of a thermal imager determines its suitability for different temperature ranges of applications. A wide temperature range can meet more practical needs, improving the applicability and flexibility of the thermal imager.

   Klein Tools IR5 Dual Laser 12:1 Infrared Thermometer

Ease of Use

Despite its wide range of functions, the Klein Tools IR5 Infrared Thermometer remains highly intuitive and easy to operate. The trigger provides quick measurements while the selection button lets you toggle through the various modes and settings.

The backlit display automatically scales to show the proper level of precision and is easy to interpret at a glance. The auto power-off helps conserve battery life if you accidentally leave it on after use.


With its broad temperature range and versatile functionality, the Klein Tools IR5 Infrared Thermometer infrared thermometer can tackle most non-contact temperature measurement needs. It’s well suited for:

  • HVAC inspection
  • Automotive diagnostics
  • Electrical and mechanical maintenance
  • Food safety and cooking
  • Identifying insulation gaps or air leaks
  • Monitoring chemical and industrial processes
  • Many other troubleshooting and inspection tasks

It’s important to note that the Klein Tools IR5 Infrared Thermometer is NOT intended for human body temperature measurements. For that application, a dedicated medical infrared thermometer is required.

User Feedback

The Klein Tools IR5 Infrared Thermometer infrared thermometer has received largely positive reviews and ratings from users. On Amazon, it currently has a 4.5 out of 5 star average rating based on nearly 1000 global reviews.

The dual lasers for targeting get strong reviews for making it easy to precisely aim the thermometer. Many users mention the different modes like min/max temperature are very useful for troubleshooting HVAC, electrical, and mechanical systems.

Accuracy when properly calibrated is praised, with most users seeing less than 2°F variance compared to contact thermometers and other IR guns. The backlit display makes it easy to read, and the auto power-off helps preserve battery life.

Some users did note the accuracy can suffer if not properly calibrated and emissivity set for the material being measured. Reflective, shiny, or transparent surfaces can be challenging. Setting emissivity correctly is critical for best results.

A few users received units with dead batteries out of the box, indicating potential QC issues on some shipments. Battery life is rated about 10 hours of continuous use, significantly less than the rating from other brands.

Overall, most users are very satisfied with the Klein Tools IR5 Infrared Thermometer, citing good accuracy, easy targeting, useful modes, and solid construction. Key areas for improvement would be battery life and quality control. For the price, it delivers reliable performance, but more expensive models do offer longer battery life and higher claimed accuracy.


  • Accurate and fast readings
  • Dual lasers for easy targeting
  • Rugged and durable construction
  • Wide temperature range
  • Useful modes like min/max/average


  • LCD could be brighter in sunlight
  • Battery cover is stiff at first
  • Accuracy suffers at temperature extremes
  • Price is higher than basic models


With an MSRP around $60, the Klein Tools IR5 Infrared Thermometer provides excellent value. It has comparable performance to models costing twice as much. The included 9V battery, carrying pouch, dual lasers, and various modes make this an affordable professional-grade infrared thermometer. Klein’s reputation for quality tools also boosts the value.


The Klein Tools IR5 Infrared Thermometer delivers reliable performance across a wide range of professional temperature measurement applications. It combines versatility, durability, accuracy, and ease of use in a compact handheld package. While it comes at a premium price point, the Klein Tools IR5 Infrared Thermometer offers good value given Klein’s reputation for quality and its robust feature set. For technicians, maintenance crews, and anyone requiring a rugged infrared thermometer, the Klein Tools IR5 Infrared Thermometer is an excellent choice.

   Klein Tools IR5 Dual Laser 12:1 Infrared Thermometer


  • Temperature Range: -22° to 752°F (-30° to 400°C)
  • Accuracy: ±2°F (±1°C) from -4° to 392°F (-20° to 200°C)
  • Optical Resolution: 12:1
  • Response Time: 1 second
  • Dimensions: 7.7 x 5.1 x 1.8 inches
  • Weight: 9.9 oz (with battery)
  • Power: 9V battery (included)
  • Certifications: ANSI, CE
  • Warranty: 1 year limited

Box Includes

  • Klein Tools IR5 Infrared Thermometer
  • 9V battery
  • Instruction manual
  • Custom storage pouch

How to Use

  1. Install 9V battery
  2. Point thermometer at target surface
  3. Pull trigger to take measurement
  4. Lasers converge to show spot size
  5. Read temperature on LCD display
  6. Select modes: MAX, MIN, DIF, AVG
  7. Adjust emissivity if needed
  8. Scan surfaces using autoscan function