Temperature Scanning: Forehead vs. Wrist

At 2M, we offer a few different types of face recognition terminals that are capable of temperature scanning. Although they mostly have the same functions in terms of access control, one terminal scans temperature from the forehead while the other one requires the user to hold out their wrist to a sensor. Which one should you choose? In this article, we will go over the pros and cons of both.

Forehead Measurement

Terminals that measure temperature from the forehead use a thermal camera to read temperature based on the amount of infrared radiation that each person emits. Thermal cameras target key locations on the face to get the closest indicator of body temperature. These terminals use face recognition in order to locate these areas. In this case, it’s the forehead, but there are some thermal cameras target the inner eye area.

The biggest benefit of forehead temperature scanning is that temperature can be detected from a longer distance. Because of this, the user would not need to do anything for their temperature to be scanned; users would just need to look into the camera of the terminal and their temperature will be automatically detected.

However, since they measure temperature from the forehead, temperature will not be able to be detected if there’s any physical obstructions. For example, a user wearing a hat that covers their forehead will not be able to have their temperature scanned because the hat is blocking the emitted infrared radiation from the forehead.

Another problem with forehead scanning is that it needs to be in the right conditions and environment for the most accuracy. Thermal cameras are particularly sensitive to ambient conditions so they should only be used in environments with a stable temperature. This is why their use is typically limited to indoors. In addition, these terminals do not function well in places with a lot of overhead light. The thermal camera uses face recognition to locate the forehead but a lot of overhead light will cause the forehead to appear warped and not capable of being detected.

Wrist Measurement

Terminals that measure temperature through the wrist still have the face recognition capabilities, but it is not used for detecting areas on the face to scan. These terminals have an infrared temperature sensor on the side of the terminal. These sensors work by absorbing the emitted infrared radiation, which is proportional to temperature.

Like forehead temperature scanning, this method is contactless. However, it does require the user to hold out their wrist to the sensor in order for their temperature to be detected. This could be a con because it requires another step than the previous device. Temperature is still scanned instantly, but not automatically since the user has to make sure their wrist is near the sensor. Another con is that the sensor requires the user to be close so there is a risk of accidentally coming into contact with the sensor.

However, temperature sensors tend to be more reliable than thermal cameras when it comes to temperature scanning. They’re not sensitive to ambient temperature so they can be used outdoors. They also do not have the issue with forehead warping because it does not use face recognition to measure temperature.


Wrap Up

Both of these terminals have the same capabilities when it comes to access control, but their main difference is how they scan temperature. When you are deciding between these two devices, you should think about what environment the terminal will be in. If it will be outdoors or in a place with a lot of overhead light, it might be better to opt for the wrist scanning terminal. If it will be indoors and you don’t want to have the extra added step of holding out a wrist, the forehead scanning terminal would be a good option. But if you have any doubts or concerns, you can always contact one of our sales consultants to help you find the best solution. If you would like to see how these 2 devices work first-hand, then schedule a free live demo today! You can also view our catalog to learn more.

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