Comparative analysis of the use of pyrometers and thermal imagers in sanitary barriers for screening febrile people

Due to the Covid-19 pandemic, many places with high traffic of people set up sanitary barriers to screening febrile people. Thermal imagers and pyrometers are the equipment commonly used to measure temperature in these barriers. In this paper, Temperature measurements performed by these instruments were compared considering the regions usually monitored in these barriers: forehead, ear, and wrist. The temperatures of volunteers were recorded after initial acclimatization, a short period of physical exercise, and a rest period after exercise, evaluating the instruments and regions of measurement and the influence of the condition of rest and physical exercise of the person. The compatibility of the performed measurements in each of these three moments was then compared using statistical and metrological tools. The outcomes showed that the pyrometer has low repeatability since its results vary widely among different measurements due to the temperature variation existing within the analyzed region and the difficulty of guaranteeing the same measurement point. As a result, a thermal imager is more recommended for taking body temperature measurements on the forehead and, preferably, on the ear. It was also determined that the wrist, in particular, has a significantly lower temperature than the central body temperature, and thus this is not a recommended region to measure body temperature when screening febrile people.