Fever Screening of employees and visitors
As employees return to work after virus related shelter-in-place regulations are lifted, it is critical for companies to ensure the health of this returning work force is not compromised by workers who may contract a virus outside the facility. While it is possible for infected workers to exhibit no signs of fever, many who are infected with the coronavirus / COVID-19 will exhibit a fever within 5 days of the onset of the infection.
Virus epidemics like the Swine influenza in 2009/2010 and the Ebola virus disease in 2014 created a worldwide demand for suitable screening techniques allowing a fast non contact detection of employees and visitors with potential fever.
The installation of the whole system including the infrared camera and its extensive software package is very easy. Also it can be re-located and set up in minimum time.
The system is password protected to prevent unauthorised changes. The cameras can be combined with our BR 20AR ambient referencing source and detect and display temperature variations less than 0.5°C.
The system works discreetly. The software singles out the people whose skin temperature exceeds the predefined value. The visual alarm quickly identifies subjects who exhibit temperature increases from the normal population allowing security staff to validate internal temperature and discreetly examine the subject for additional symptoms.
If necessary the software offers the possibility to take automatically IR image snapshots when a person trips the alarm. Thermal images with temperature measurements can be stored whenever a temperature exceeds the pre-set threshold.
Absolute temperature measurement accuracy
Most infrared cameras with 8-14 μm spectral response are specified with an accuracy of +/- 2 °C or 2 % of the reading based on deployments in industrial environments in a wide variety of ambient conditions from 32 °F to 122 °F.
Many infrared cameras with microbolometer sensors are promoted today with accuracies of +/- 0.5 °C or better. These accuracies cannot be achieved without the use of a black body reference source. The source needs to be stable, have high emissivity and positioned in the scene proximate to the subject to be scanned.
Our BR 20AR ambient referencing source can be combined with our PI 400i T010. The black body is equipped with a 16 bit digital temperature sensor with +/- 0.1 °C accuracy. By integrating this highly accurate reference signal to our PIX Connect software, we can reduce camera uncertainties resulting from device adjustment, ambient temperature drift and short term stability down to a system accuracy of +/- 0.5 °C with a confidence interval of 95 %.
The use of a reference source and 0.5 °C measurement accuracy are recommended in the latest FDA guidance issued in April 2020 and the Optris PI400i and BR20 comply with these recommendations.
The real ability of an IR camera based screening system to detect subjects with fever lies more in the ability to discern which external face temperatures, as measured at the tear duct/ Medial canthus, are significantly higher than those in a given population exposed to similar ambient temperature conditions.