Thursday, January 1, 2015

Tips: Capturing crisp and clear infrared thermal image

Happy New Year, readers! I wanted to start the year by sharing some useful tips on how you can capture crisp and clear infrared thermal image. Thermal imagers or thermal cameras available on the shelf today are quite intuitive and easy to use. However, getting the best thermal image and then interpreting it later requires knowledge and experience. Here are some tips that can help you be better prepared when you are out in the field.
  1. Get the right focus on the target area for more accurate temperature readings. There are several types of focusing mechanism available – fixed-focus, manual focus or auto focus, with the latter being the most advanced. Take your time to get it right at this stage because this cannot be edited later!
  2. Perform a quick scan on the targeted area that you are inspecting. Set both the temperature range and scale to auto mode, to quickly get the temperature range of the area. Once done, you can fix the temperature scale by enabling the manual mode, to capture a more stable image. Change the mode quickly with the Auto/Man quick access- button (press-and-hold) on the U5855A TrueIR thermal imager.
  3. Once a suspected hotspot is found, manually refocus on the hot spot area. Always validate if it is a real hotspot by checking for any possible reflective heat sources or solar loading effect, if the inspection is done in an open area or under the sunlight. Move from side to side to eliminate possible external or reflective heat sources.
  4. Check the surface condition and material of the hotspot area and apply a suitable emissivity coefficient factor, Ɛ. Note: If the object’s surface is polished or shiny in nature, both the Ɛ and emitted IR energy will be low. These surfaces can also reflect IR energy from other sources. In such cases, the low Ɛ and external reflected IR energy typically produces an inaccurate temperature measurement. Ensure these values are compensated by setting the right reflected temperature, ambient temperature and humidity of the area of inspection.
  5. Capture and save the IR image for reporting purposes. Extra identification and information on the hotspot area can be done by note/photo tagging (with TrueIR thermal imager, user can capture and tag up to 3 visible photos to each of the infrared images captured) or with simply writing it down in notebook.
Sample infrared thermal image of electronics PCB board
taken with U5855A TrueIR thermal imager








Sample infrared thermal image of solar panels
taken with U5855A TrueIR thermal imager



Perform post-IR thermography analysis, such as adding additional temperature spot measurements, box measurements,line or histogram analysis to further support the findings. Correction parameters, such as emissivity, reflected & ambient temperatures as well as color alarm setting can also be done during post-analysis. TrueIR thermal imager comes with free downloadble software  (www.keysight.com/find/TrueIR_ART) that can be used for analysis and reporting purposes.  





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