It’s early morning at the campus gate. You feel the sting of the icicle-sharp winter air when you open your car window, presenting your forehead to have your temperature taken by the screening terminal.
Your temperature appears on the screen. “Authenticated,” an automated voice from the unit says, giving you the green light to swipe your entrance card and enter the campus.
The screening process has not always gone as smoothly. At the beginning of last winter, our staff at the gates struggled to keep the non-contact, handheld thermometers warm enough to function properly.
The problem is that the minimum operating temperature for many kinds of readers is 10°C, which is far above the temperatures we experience on a winter morning in the North West and Gauteng.
Clipping winter’s wings
Fortunately, the engineering division of IT’s Electronic Services solved this problem. Their solution was to encase the screening unit so that its components could be temperature controlled using a heat pad, while still proving a clear view of the person’s face.
After initial research, they ordered a test unit to ensure that it functioned as desired and would work in the environment that the university required. The temperature controller was also tested, with tests to ensure that it would not affect the readings of the camera.
How this scanner benefits us
This non-contact engineering solution decreased the load on Protection Services staff and has lowered the risk of spreading Covid-19 since it does not require a person to take the measurements.
In addition, automation means slightly faster scanning at gates, relieving congestion.
Jaco Crause is an engineer at IT’s Electronic Services department.
clipped winter's wings
How the screening terminals work
“Our access control terminals at the campus gates use multiple cameras and an onboard card reader to allow face recognition, temperature measurement and card access verification,” explains Jaco Crause from IT’s Electronic Services.
At the moment, only the temperature measurement and mask detection functionalities are being used.
The device uses two camera lenses to build a 3D perspective, do face and mask detection and locate the position of the forehead.
“The top lens is an infrared camera that picks up the invisible light emitted by everything based on its temperature,” says Jaco. “The device uses the position of the forehead – as determined by the visible light cameras – as a reference for where to measure the temperature with the infrared camera.”
The dos and don’ts
when scanning your temperature
When you scan your temperature, make sure that you are close enough to the device to see your face clearly on the screen.
Remember that outside factors such as wind and sun influence your skin temperature, so try to minimise these as much as possible before taking the measurement.