Acal BFi's technical specialists have proposed application-specific solutions, working with market-leading suppliers such as FLIR, to help quickly specify and supply reliable products for Elevated Body Temperature systems. These products are specifically designed to identify individuals with elevated temperatures, who could potentially have COVID-19.

Although no thermal infrared cameras can detect or diagnose a virus, they have a long history of being used in public spaces, such as airports, train terminals, businesses, factories, and concerts, as an effective tool to measure skin surface temperature and identify individuals with an Elevated Body Temperature (EBT).

To optimise EBT detection, Acal BFi recommends the following field-proven techniques:


How our technical experts and specialist portfolio can help

We recommend the operating procedure specified on ISO/TR 13154:2017, which clearly specifies "The individuals to be screened are channelled into a single file and caused to stop or pause so that the screening thermograph can capture the facial temperature distribution one at a time".


Measuring temperature in the corner of the eye to improve accuracy

EBT screening without physical contact, the most reliable technique is to use an infrared camera to measure the temperature on the hottest part of the face, in the corner of the eye at the tear duct, this is the only part of the face which is truly representative of the individual’s inner-body temperature.

Experts have confirmed that there is a correlation between the eye canthus temperature (tear duct area) and overall body temperature. Measuring this area is a field-proven technique to provide the most accurate indication of the actual body temperature of the screened individual, whatever the environmental temperature conditions.

To apply this technique, we recommend using a thermal infrared camera's which measures the temperature of this small area with at least 9 pixels for accurate results.


Ensure your system provides precise results using a temperature reference blackbody for calibration

If you are using a FLIR high-end thermography camera model (FLIR A320, FLIR A400, FLIR A700) featuring their unique Automatic Temperature Compensator (ATC) that automatically adjusts for ambient conditions to minimise false readings, then the use of a blackbody is not a requirement. You can use the “TEMP-SCREEN” screening mode, which uses a healthy person's face as a temperature reference to measuring the difference. Then, the screening mode provides an alert if any individual's face temperature is more than 2 °C above the reference temperature. Using the TEMP-SCREEN mode rather than a blackbody requires additional maintenance as it is recommended that the reference temperature is updated every 15 min.

If you are using a FLIR camera module (FLIR Tau2, FLIR Lepton), then the use of a blackbody is required for real-time radiometric calibration of the camera. Using a body temperature reference blackbody as part of your system provides more consistent results because after configuration, the blackbody automatically calibrates the system no matter what changes occur to the environmental temperature. We recommend the SBIR Nightingale infrared blackbody temperature which has been recently developed to provide stable, uniform and accurate temperature measurement with IR cameras by Santa Barbara Infrared, a world-leading infrared blackbody manufacturer.

Additional screening using IR forehead thermometers

IR cameras can be used as the first line of EBT detection, however, if the temperature of the skin (especially the corner of the eye and forehead) is above average temperature, then the individual needs further testing. A highly accurate method of further checking an individual’s body temperature is to use an infrared forehead thermometer like the FLIR Extech IR200 Non-Contact Forehead InfraRed Thermometer.

Additional screening using IR forehead thermometers

•  For OEM’s building their own systems
• Turnkeys systems for manned security posts with guards