Best Practices for Body Temperature Detection Systems

Wednesday June 10, 2020

This Article will follow the CDC and FDA regulations and guidelines. 


There are many companies jumping into selling a temperature detection system to the state and local Governments, hospitals, airports, and local businesses. But, do they know everything about what they are selling? Can they run these systems properly making them accurate and safe for public use? Anyone can get behind a car and drive it into a wall by accident because they don’t understand how to properly operate it. The same thing can happen with a Temperature Detection System


     The first thing you should ask is “Does their firm have a certified thermographer on staff?” If they don’t, they will most likely not know what they are talking about and you will get a low quality system that is being resold to you so they can make a quick buck. Businesses that are doing this do not know how to operate Temperature Detection Systems properly.


      Is your system NDAA compliant? NDAA compliance means that your temperature detection camera equipment chips do not come from certain banned (banned from selling to the USA Government) Chinese companies and their subsidiaries that could potentially leak your information…or worse, spy on you!  


Does your system have a HSRP device (blackbody)? HSRP Stands for Heat Source Reference Point (blackbody) device that will allow the camera to tell the correct temperature at the distance the HSRP device is away from the camera, even if the room temperature does change throughout the day treat it as a reference point for the camera to know the temperature at that distance away from the camera. (note cameras only get a color and convert that color into a number but that is another paper)


     Can your system scan muti-people at once? In my opinion this is a silly question, but it’s often asked. Most systems will say yes to this question because everyone wants to scan multiple people at once. The fact is, the best practice according to FDA and CDC guidelines is you should only run one person at a time for best accuracy though the system. Why is this? Think about it! The HSRP (blackbody) device tells the camera what the correct temperature(color) is at a given distance away from the camera; every foot you are away from the HSRP device you will be off by 0.1 degrees roughly. If you are in a room full of people, let’s say 6 in view of the camera, every person that is not next to the HSRP device (5) will be given an inaccurate reading. That’s why it’s so important to run the system correctly with just one person at a time. You’ll also need to follow the 6 feet rule anyway. If you take that into consideration, one at a time at 6 feet apart should tell you how you need to run the system.


     Is your system’s sensor accurate enough? The FDA recommends an error of ±0.5°C or better, so when you are looking for a system make sure it is better than what they recommend. I would recommend ±0.3°C or better. A lot of systems out there are ±-2°C  to ±-5°C  and that is not ±0.2 or ±0.5 that is 2 and 5 degrees difference, which is way off.  Do not purchase a system over ±-.5°C degrees as you are doing yourself and your customers or employees an injustice.  Another thing to look at with your sensor is how many pixels it can tell the temperature from, some cameras can only tell the temperature of 6 points on the screen while others can take a temperature reading from each pixel on the screen. So take a 384×288 camera that is over 110,000 points of temperature taking on that image.     


     Do not wear glasses or a hat please! The system will not see through these items. Thermal cameras are very sensitive, so there are a lot of do’s and don’ts. For example, something to think about is if you have a glass barrier like a window to your building. Can a thermal camera see through glass?  YES or NO?

     Check out the example image below: On the right side, you can see the person with the visual camera, and on the left side is a thermal camera image.  Both pointing at the same area.  You can see the person on the left  side is “invisible” to the thermal imaging camera.

temperature detection with glass results

temperature detection with glass results Learn more here

 So if you are a company who wants to pick up the temperature of its customers or employees through the front door or window, or even a car window the answer would be no. You need a clear line of sight without any interference to scan for temperatures. If you sell these kinds of systems and you did not know that, you should really go take a course in thermography and know what you are selling because people’s health is depending on you selling an accurate product. Other things you need to look out for is wind and distance away from the HSRP (blackbody) device.  Air and distance away from the HSRP device will make the system less and less accurate the more space between the device and target.


     Last thing you may also be asking is “even if I have a clear line of sight is there anything else I need to know?”.  The answer is yes reflective materials like metal can interfere with your systems temperature readings see example below: visual side you can see a person, but you can not see the person taking the picture. If you look at the thermal side you see the reflection of the person taking the picture in the image, but of course you do not see the person through the glass. The temperature reading of their face on the visual side is how we get 98.7 degrees. Reflective materials in front or behind the camera are easily picked up from the thermal side so pointing at a medal, glass or anything that is reflective is going to be a big no.

Reflection off of glass can interfere with temperature detection systems

Reflection off of glass can interfere with a temperature detection reading


    Folks, be safe and responsible please. I am in Austin Texas and travel a lot for work and see many people not wearing masks across our country or keeping social distance.  I hear many things like there is no virus, it is just a hoax or lie to control people. I even see the opposite like people fighting if you get into their 6 foot space.  Let me tell you that this is a very real threat so you should not take it lightly. This is a serious threat that is not going away. The population is only less than 5% infected which means as we let go a little of the lockdown you can be sure we will hit a lockdown state again, or face many more deaths!  Keep your masks on and keep your distance! If you are an organization, get a system in place to help scan for high temperatures to make sure you are not allowing the spread of people that could be sick.