Today there are a lot of companies jumping into the market with all sorts of products, cameras, software, etc. to meet the exploding market of solutions for the screening of people for COVID-19. 

There are some very good cameras/software/systems for doing this, but for every solid solution, there are hundreds, if not thousands of snake oil salesmen and products that promise you the world, and it is giving the good products/solutions a bad name. 

Infrared/thermal imaging cameras do not actually measure temperature — they measure the radiated energy of the surface area that they are viewing. That radiant energy is then converted into a thermal image with apparent temperature measurements. It is important to remember that this radiated energy may or may not be a function of the surface temperature.  

There are many variables that must be considered when attempting to get an accurate temperature measurement.  Especially when you are trying to measure someone’s body temperature.  

First, we must define, where we are going to be trying to measure on the body so that we can establish a consistent, reliable measurement point. 

The Tears Ducts of the human face are the only place where you will get repeatable/reliable measurements.  They are a small area, that you must have a clear line of sight with the camera to image correctly, and the person can not be wearing any eyeglasses. 

Outside body temperature is not the same as inside, so you will not be reading 98.6 as shown in the image above where the tear ducts are 91.7 & 91.9F.  But they will give you the best area to measure that is going to be the most consistent and reliable. 

You cannot use the: 

  • Forehead or Hair 
  • Noise 
  • Neck 
  • Mouth 
  • Hands or wrists 
  • Other parts of the body 

In the above images, they are using a spot radiometer, which does not have the required measurement ability to measure someone’s body temperature correctly, and they are not being used to image the tear ducts of the face.  This is a very common practice that simply will not work! 

You must also control the environment from influence your measurements, for example, you can not perform these measurements outside, where you have the Sun, Wind, Rain, etc.  They must be done indoors in a controlled environment without any drafts or other radiant sources nearby.  

Other considerations for the imagine include: 

  • Resolution of the camera’s detector. 
  • The sensitivity of the camera’s detector. 
  • Thermal Drift of the detector. 
  • Distance between the camera and the person. 
  • The angular field of view of the camera lens. 
  • Ability to clearly have a solid Measurement Field of View of the Tear Duct. 

In addition to making sure that you have met all of the above requirements, you will also need a Blackbody Calibration Source in the field of view to be able to compensate for the Thermal Drift of the camera. 

 

In the two images above, you cannot use an IR camera that is designed for industrial applications to scan people for COVID-19.  These cameras were never designed for this purpose and cannot meet the requirements. 

 Only IR Cameras that have to meet the FDA guidelines and follow the ISO/TR 13154 standard are acceptable. 

For more information on what cameras are designed for COVID-19 please check out the cameras from Infrared Cameras Inc.

Furthermore, a trained professional thermographer with the necessary knowledge for calculating a very precise temperature is needed to monitor the equipment and ensure that the measurements are accurate because lives depend on it. 

If you have any questions Contact us anytime, we are looking out for you!