Thermal Imaging


Thermal Imaging, or Infrared Thermography, is a non-contact technology that measures or “sees” infrared wavelengths emitted from objects, and then converts the temperature information into image. The image features a color palette that represents a temperature range of the image displayed.

Hot spots or a rise in temperature often indicate problems or potential failure. Thermal images are fully radiometric by measuring and storing temperatures at every point in the image.

Benefits of Thermal Imaging

Thermal Imaging technology has created a more efficient and safer method of measurement. The benefits of thermal imaging are listed below:

Lower Costs

  • Incorporating thermal imaging into a predictive maintenance program can save money by locating potential failures and hot spot that could cause expensive manufacturing downtime, production losses,power outages, and fires.
  • Extending equipment life with scheduled outages and reducing employee overtime.

Increase Productivity

  • Thermal Imaging provides fast and accurate measurements of objects that are difficult to reach, altered by touch, or impossible to shutoff
  • Troubleshoot and make informed decisions by viewing the thermal performance of equipment in seconds.

Reduce Risk

  • Thermal Imaging allows accurate temperature measurements from a distance for objects that are moving, very hot, and dangerous to contact.
  • Decreased unplanned downtime and the risk of arc flash with regular inspections while maintaining a safe distance from equipment.

Critical Specifications of Thermal Imaging

There are three main specifications that are critical in the process of selecting a thermal imager:

  • Temperature range,
  • Thermal sensitivity (NETD), and
  • Resolution

Temperature Range

When selecting a thermal imager, evaluate the temperature range that will be suitable for your applications. For industrial applications, the temperature range is the number one specification to consider. Industrial thermal imagers feature a wider temperature range to accommodate facilities that have high-temperature equipment such as boilers and steam systems.

Thermal Sensitivity

Thermal sensitivity, or Noise-Equivalent Temperature Difference (NETD), measures the smallest temperature difference that a thermal imaging camera can detect in the presence of electronic circuit noise. Cameras with a low NETD will detect smaller temperature differences and provide higher resolution images with increased accuracy.

Thermal sensitivity is measured in milliKelvins (mK). Cameras are more sensitive with values at the low end of the scale. For example, cameras with 50 mK are about 4 times as sensitive as a camera with 200 mK. The more sensitive (50 mK) cameras provide a wider temperature difference, resulting in more colors on the thermal display.


  • Detector resolution plays a pivotal role in image quality of thermal imaging cameras. Higher resolutions provide precise and reliable measurements of smaller targets from further distances, creating sharper thermal images. The higher the detector resolution, the more accurate the camera.
  • When evaluating between detector resolution and display resolution, be aware that the quality of the thermal image and its data is always determined by the detector resolution.
  • For example, if the built-in screen has a resolution of 307,200 pixels (640 x 480) but the thermal detector resolution is only 19,200 pixels (160 x 120), the thermal image can only be measured by the resolution
    of the thermal detector.
  • The examples below that as the thermal detector resolution increases, the image detail becomes clearer and the temperature
    at a single point is more accurate.