Many organizations are at risk of disruption to operations because of the coronavirus, or possible future pandemics. Sonic Systems offers thermal Imaging solutions from FLIR that can help screen frontline employees for elevated body/skin temperature – a possible sign of infection – before they enter crowded workspaces. Organizations that use these screening systems can help provide a safe and secure workplace for a productive workforce.
The Pentagon Visitor Center in Washington, D.C. used the fully integrated EST™ system recently for rapid screening to protect front line workers. The camera system screens for elevated skin temperature as part of COVID-19 prevention measures.
Because thermal imaging cameras can detect and visualize heat, it seems logical to think they can be used in non-contact screenings to detect elevated skin temperature. But thermal imaging isn't appropriate to every camera model or brand.
Make sure the thermal imaging camera offers temperature measurement as well as a high thermal pixel resolution and accuracy. Popular FLIR models like the Exx-Series and T-Series cameras are examples of cameras that meet these base specifications. They also offer a built-in screening mode designed to streamline elevated skin temperature applications.
As a non-contact screening tool that quickly detects elevated skin temperatures, the FLIR A700-EST™ IS offers an excellent first line of defense against potential health risks. Integrated and scalable, this solution combines the innovative FLIR A700 thermal camera with a high definition, user-friendly interface. Easy to use, the FLIR A700-EST IS quickly detects and visualizes heat to identify individuals with raised skin temperatures. A thermometer or other medical device can then provide further screening.
However, only thermal imaging cameras that provide adequate thermal resolution and measurement accuracy, as well as the correct preparation and scanning methodology are appropriate for this use. To help learn more about the best practices for this non-contact screening option, read the FAQ offered by FLIR.
No, a thermal imaging camera cannot be employed to detect or diagnose an infection. They are, however, used in public spaces such as airports and hospitals and by essential services such as manufacturing and shipping as an effective tool for measuring skin surface temperature. When somebody is identified as having an elevated skin temperature, they can then be screened by medical professionals using additional tools such as an oral thermometer.
A FLIR thermal camera will detect heat radiation and can be deployed to determine the surface temperature of people and objects. With this capability, FLIR thermal cameras are often used as a non-contact screening tool to detect differences in skin surface temperatures and pattern changes. FLIR is registered with the US FDA to contribute a range of its thermal products to screen for elevated skin temperatures to be used in connection with additional screening tools.
Here are a few tips to ensure correct measurement performance from a FLIR thermal camera:
The US Food and Drug Administration has registered the following FLIR thermal cameras and non-contact thermometers to detect differences in skin surface temperatures:
Handheld Thermal Cameras
FLIR Cameras E53, E95, E85, E75, T530, T540, T620, T640, T840, T860, T1020, T1040
Fixed-Mount Thermal Cameras
FLIR A320 Tempscreen, A300, A310, A315, A325, A615, A655, and A400/A700 (Advanced Smart Sensor configuration)
Some FLIR cameras include a Screening mode that issues an alarm when an object or person is detected to have an elevated temperature compared with a sampled average temperature value. Screening mode is not an absolute temperature measurement. Activating the Screening mode will turn on a measurement box and screening data on the camera’s screen that includes:
In Screening mode, the camera operator records the skin temperature data from ten people at the testing location to establish the Sampled Average Temperature. An Alarm Temperature is then set by the operator by assigning a delta, which is typically between 1°C and 3°C, resulting in an alarm temperature that is 1°C-3°C greater than the Sampled Average Temperature. Each person is then screened one at a time, and their Measured Temperature is compared against the Alarm Temperature.
The Sampled Average Temperature should be updated frequently throughout the screening operation period. This will help account for many potential variations during screening throughout the day, including fluctuations in average body temperatures due to natural environmental changes, such as ambient temperature changes. The screening mode feature reduces the requirement for absolute accuracy throughout the day. It even self-calibrates to remove potential errors in absolute accuracy from camera to camera.
The FLIR camera screening mode is highly stable at room temperature. This makes them well suited for this application. Cameras that offer Screening mode include:
FLIR Cameras E53, E95, E85, E75, T530, T540, T620, T640, T840, T860, T1020, T1040, A320 Tempscreen.
In order to obtain a good temperature reading, the intended target be as close to the camera as possible (with respect to the camera’s minimum focus distance). Different camera distances may require a different lens. For instance, if the operator placed the camera at a considerable distance, FLIR may recommend a telephoto lens. Therefore, both distance to the target and focus are important considerations.
All the intended targets must be in focus during the screening process to create a good image. In addition to focus, several additional functions and settings will affect the quality of the image, with some functions and settings impacting the image more than others. Functions and settings that need to be set and/or adjusted include the following:
For the FLIR non-contact thermometer (see section below regarding non-contact thermometers), the most advantageous measurement distance is from 5 cm to 15 cm (1.9 in to 5.9 in).
FLIR thermal cameras can detect the temperature differences with temperature measurements between -20°C and 2,000°C (-4°F—3,632°F). The standard FLIR product accuracy specification of ±2°C or 2% of the temperature reading at 30°C (86°F) ambient environment applies to all temperature ranges it measures and for the multiple applications for which it can be used.
FLIR thermal camera with Screening mode can attain accuracies of ±0.5°C (0.9°F) at 37°C (98.6°F), by using the camera in stable ambient conditions, using only humans, and updating the reference samples according to the population being screened.
There are, however, many factors that can alter the accuracy of thermal cameras, such as focus, distance, the emissivity* of the target, the ambient environment, and the speed at which the temperatures are captured.
*A target’s emissivity is its ability to emit thermal radiation. For example, clothing, ceramic mugs, and even human skin have high emissivity, while polished metals have low emissivity.
When screening for elevated skin temperatures, there are both advantages and disadvantages to using a black body. The system’s performance in this application can be improved by including a black body in the camera’s field of view. This configuration is supported by FLIR thermal cameras.
However, FLIR has thermal cameras with temperature screening mode that don’t require the use of a black body. The handheld versions of these cameras are all embracing, minimizing points of failure and maximizing flexibility and mobility. Screening mode also helps to account for many potential deviations during screening throughout the day, including changes in a person’s temperature due to natural atmospheric fluctuations. Screening mode reduces deviations in absolute accuracy throughout the day. It even accounts for any potential variation in absolute accuracy between cameras.
Using a black body for elevated skin temperature screenings can cause challenges. Firstly it is more expensive and complicated to include an extra piece of hardware in the solution; it makes mounting, powering, and ultimately maintaining it more complex. Including a black body also introduces another potential point of failure into the overall solution.
In order to get accurate measurements, proper focus on the black body is essential. For a black body to be effective, it must be situated in the same plane as the person being screened. A black body that is considerably closer or farther than the individual being screened will be out of focus and will not serve as an accurate reference source.
If the screening solution must include the use of a black body, FLIR recommends following these requirements, as explained in ISO/TR 13154:2017:
FLIR recommends that thermal camera operators earn at a minimum Level 1 thermal imaging certification through certified thermography courses such as the Infrared Training Center. While not a medical training or medical certification, this certification provides a basic level understanding in thermography. The Infrared Training Center also offers more advanced training. To learn more visit: www.infraredtraining.com.
We cannot name specific customers or comment on current sales, but we can say that our thermal cameras are used by customers at ports of entries and high-traffic locations in several countries, including the US, China, Hong Kong, Taiwan, Singapore, South Korea, Thailand, Philippines, and Malaysia.
During the SARS outbreak in 2003, FLIR noted an increase in the use of thermal cameras for skin temperature screening.
FLIR offers an IR non-contact handheld thermometer under our Extech brand. Non-contact thermometers are usually employed in a handheld fashion to screen an individual’s forehead. The operator points the non-contact device at the individual from a specified distance of 5 cm to 15 cm (1.9 in to 5.9 in); the thermometer can measure temperatures from 32°C to 42.5°C (89.6°F to 108.5°F).
Specifications for a non-contact thermometer include:
For FLIR non-contact thermometers, an adjustable alarm alerts the user—either visually or audibly—when the temperature is higher than the programmed limit. The non-contact thermometer has an ample backlit LCD display to show temperatures.
The recommended FLIR non-contact thermometer has been calibrated to an accuracy of 0.3°C (0.5°F) with 0.1°C/°F resolution.
The Extech IR200 is an entry level device in our elevated skin temperature screening portfolio. The IR200 is an economical, non-contact skin measurement tool for front line elevated skin temperature screening applications. But like other forehead IR thermometers, the IR200 does not have the same advantages as one of FLIR Screen EST enabled thermal camera solutions. FLIR thermal cameras designed for elevated skin temperature screening provide a much higher performance approach to screening for elevated skin temperature because they have: built-in camera stability control, automatic temperature measurement at greater standoff distances without operator input, and the ability to screen the entire face pinpointing the inner canthus area near the tear duct.
The IR200 uses a spot pyrometer-based non-contact temperature measuring technology. It is accurate to 0.3°C (0.5°F) with 0.1°C/°F resolution when measuring skin temperatures between 32.0°C to 42.5°C (89.6°F to 108.5°F). For more information visit: Extech.com.
When properly used, it can be an effective tool to help detect an elevated temperature to determine if that person should be subjected to further screening.
Each IR200’s object mode is calibrated with multiple known temperature targets and is programmed with an offset to translate to body mode, during production inspection. The IR200 calibration can also be altered by the user per the owner’s manual.
Unlike many of the non-contact IR thermometers being advertised by other companies, FLIR recommends the IR200 be used solely as an initial screening tool, and not a medical grade thermometer capable of giving a user an accurate reading of an individual’s core body temperature. This recommendation is also listed on the Extech IR200 web page, as shown here:
This thermometer is intended for screening individuals or monitoring a person for potential elevated skin temperatures. The IR200 is not a substitute for a clinical thermometer. Always use a clinical thermometer when high accuracy body temperature measurements are needed.
Thermal imaging cameras can be an effective screening tool to detect individuals with an elevated skin temperature. Monitoring of this type can provide helpful information when used as a screening tool in high-traffic areas to help identify individuals with an elevated temperature compared to the general population. That person can then be further screened using other body temperature measuring tools.
Although thermal imaging cameras are primarily designed for industrial and night vision applications, public health organizations have used FLIR cameras around the world at airports, seaports, office buildings and other mass gathering areas to deliver rapid, efficient screening in high traffic areas. FLIR thermal cameras are especially well suited to this because they can provide a temperature reading of an individual’s face in a matter of seconds.
A thermal imaging camera generates infrared images or heat pictures that show small temperature differences. This allows thermal cameras to construct and continually update a visual heat map of skin temperatures. FLIR thermal imaging cameras are very sensitive, capable of measuring small temperature differences.
Many of the FLIR thermal cameras that are appropriate for measuring skin temperatures also feature built-in functions such as visual and sound alarms that can be set to go off when a specified temperature threshold is surpassed. The operator can then immediately decide whether the individual should be subjected to further screening with additional temperature measurement tools.
As the thermal imaging camera generates images in near-realtime, the total evaluation process takes mere moments. This makes thermal imaging technology very useful for quickly screening large numbers of people.
A person’s general skin temperature is usually not equal to the person’s core temperature. However, that doesn’t diminish the usefulness of a thermal camera. Thermal cameras are useful in this role because the goal is not to measure absolute skin temperature, but to differentiate individuals who have an elevated skin temperature compared to others while also considering the environmental conditions of the location.
Certain FLIR camera models offer an elevated skin temperature screening mode that is useful in comparing the individual being screened against the temperature of other people previously screened. When in Screening mode, the camera operator can record ten thermal images of faces that the camera automatically averages as a reference.
Any areas on the subject’s face that are higher in temperature than a predefined temperature value can be displayed as a designated colour on the thermal image. This built-in alarm allows operators to make an immediate decision as to whether the subject needs further screening with additional screening tools. As well, some FLIR cameras are furnished with an audible alarm that can be activated to sound if the detected temperature is higher than a predefined value.
FLIR cameras are being used in airports, seaports, office buildings, warehouses, and more high-traffic areas to screen people coming in and out for the coronavirus. It is a quick, non-contact method that is safe for both the camera operator and the individuals being screened.
Sonic Systems can help you design and install the right solution for your organization. Contact us for a free consultation.