Many companies in India have become reseller or seller for Thermal Imaging camera for fever detection in India and there seems to be lot of confusion/doubts about choosing the right product/solution for their requirement.
Here is few tips which may help people choose the right product for their requirement.
Continuous mass screening – In this screening, many people walk in lobby of hotel, malls etc. where people do not walk in a single file. It can also be a case where workers enter into a factory in multiple lines. In this, Thermal Imager Camera with visual camera a face detection would be suitable.
One by one voluntary checking – Most probably, this is the screening system which will fulfill most requirement in India. Office goers entering the office one by one, either in single line/queue or multiple lines/queues or different entry gates. Here, a person can stand in front of Fever Detection device, gets her body temperature measured looking at the thermal camera an proceed if green lighted. Here, both Thermal Camera based fever detection system or Pyrometer based fever detection system can be used for each gate or queue.
Now the technical part. What should be minimum technical specification of thermal camera or visual camera ?
For mass screening, thermal camera should have minimum 0.5 degree accuracy in measuring temperature. Also, ideally more resolutions, better the camera, but thermal camera should have minimum 384X288 Pixels resolution. We recommend at least 640X480 pixels for mass screening for an area of 8 meters by 6 meters from distance of 1 meter to 9 meters from the Thermal Camera, assuming the thermal camera has 12mm lens. While use of black-body may increase the accuracy of the measurement by 0.1 or .2 degrees, but it may not suitable to keep them in the open.
For one by one voluntary screening, most probably, pyromter based screening will be good enough or low resolution thermal camera like 80X80 pixels should be good enough with same accuracy as above. Most probably, the visual camera or normal camera does not matter much here except that it should have minimum resolution of 2MP.
Origin of the product : Due to lock-down and COVID19 situations, most probably, it will be good idea to buy thermal imaging systems or any product made in that country, ie for India, one should prefer Make In India mainly due to transportation/support uncertainty.
Integration with other system : Ease of integration with other systems like attendance system, display system should be considered while buying a fever detection system. So, any thermal camera manufacturer with strong software development team which can provide software integration support should be preferred.
Finally, a Fever Detection System is essentially an temperature measurement system, not a camera system. So, one should check the background of the company which makes thermal imagers if they have experience in making radiometric thermal cameras.