For a long time, thermal solutions such as thermal cameras and imagers have been used for surveillance. However they also have temperature-based screening and access control applications, which have gained more importance nowadays with the spread of the novel coronavirus, COVID-19.
For a long time, thermal solutions such as thermal cameras and imagers have been used for surveillance. However they also have temperature-based screening and
access control applications, which have gained more importance nowadays with the spread of the
novel coronavirus, COVID-19.
Needless to say, the human body emits infrared radiation that, while not visible to the naked eye, can be detected by various IR and thermal solutions. Applications vary. For those of us working in security, these solutions, for example thermal imaging, are used to detect intruders or other objects during nighttime or inclement conditions. When you need to monitor the perimeters of large military bases or prison compounds in the middle of the night, thermal imaging can be quite helpful.
Yet thermal solutions have other applications as well, especially in the area of access control and screening at airports, enterprises and other end user entities to detect elevated body temperatures and ultimately help prevent communicable diseases.
These solutions have proven helpful during past outbreaks of diseases such as SARS, the bird flu, the swine flu and E-bola. Now, thermal solutions have come to light again in the wake of COVID-19, which as of Feb. 27 has infected 82,166 worldwide and killed 2,804. Countries have imposed restrictions on travelers from the more affected regions, and thermal solutions are needed more than ever at end user organizations to detect the temperatures of individuals.
That said, below are thermal solutions that are commonly used for access control and screening purposes.
Infrared temperature sensors
Infrared temperature sensors can be divided into two categories, contact and non-contact. For offices or other end user entities that screen people during rush hours when they come to work, contact is not feasible. In this regard, end users may find useful non-contact IR temperature sensors, which typically employ thermopile sensors designed to measure temperature from a distance.
“Non-contact infrared thermometers (NCITs) can provide temperature readings within seconds. Most NCITs measure temperature over the central forehead area, but temperature over other body surfaces may also be measured,” said the UK National Institute for Health Research. “Since the use of NCITs does not involve any body surface contact, the risk of cross-infection is negligible and neither disinfection nor disposable probe covers are needed.”
Thermal cameras
IR thermometers take people’s temperatures one at a time. While that may be sufficient for offices, companies and other smaller-scale entities, doing so for large numbers of people is impractical. For screening of crowds at large-scale end user entities, for example airports, operators are looking for a faster, contactless and reliable method for detecting elevated temperatures.
That said,
airports and similar entities turn to
thermal cameras, which produce thermal images or heat pictures that display temperature differences, helping operators to detect those with high or abnormal temperatures. Since thermal cameras produce images in real time, the total evaluation process takes less than a second, making these cameras an effective and ideal tool for rapid screening of people.
It’s interesting to note that while in the screening process, administrators usually set a threshold (for example 37.5 degrees Celsius) above which the person may be singled out for further examination, such procedure may be flawed as a person exiting a cool environment, for example inside a plane, may have a lower body temperature yet still have a fever. That’s why technologies such as FLIR’s automatic temperature compensator can be helpful. It compares a person’s temperature with those of others; once a person is detected to have an abnormally higher temperature from the rest, he/she will be singled out.
Are you interested in reading a guide to selecting body temperature cameras? Check here to download this buyer's guide.