No-Contact Infrared Thermometers 101 - How Do They Work?
There is no denying that the pandemic situation has changed the world as we knew it. New measures are being undertaken every single day, and technological innovations have surged. Masking, social distancing, and sanitizing are reigning supreme, and industries are keen to take all necessary precautions to prevent the virus from spreading. While more than 70,000 cases were registered in the US at the end of March, the country is in no mood to give in to the virus. Hence, they are taking all possible measures to keep the people safe and the economy rolling. Lockdown is regarded no more an option, as we have the vaccines now, but there is no end to the number of precautions one can take. Besides the three most important weapons (masks, social distance, and sanitizers), we also have the provision to keep infected people away from healthy ones by restricting the former’s movement. And what helps us do that properly?
You are right! Fever scanning it is!
According to the CDC, fever is one of the commonest symptoms of the SARS-COVID infection. From the beginning of the pandemic, i.e., the last year, officials have been measuring core body temperatures of people at the entry points and exits of every public space. People with fever, no matter what reason, are barred entry into these spaces. No-contact thermometers are being used for the same, to keep everyone safe. But questions have been raised regarding the efficacy of these thermometers. New devices have been launched in the market to resolve the issues concerning the efficacy of conventional IR thermometers. Scroll on to know about the challenges and their possible solutions of no-contact thermometers in the pandemic situation.
What are IR thermometers and how do they work?
IR thermometers, or Infrared thermometers, are used to measure temperatures of dangerous objects from a safe distance. These are used by multiple industries to measure surface temperatures of various equipment, toxic substances, and are as fast, to prevent malfunction due to temperature elevations. Of recent, these thermometers are being used to scan body temperatures for signs of fever, a symptom of the ongoing pandemic. When nothing else was available, no-contact thermal guns were used to scan the core body temperature of the common people at places such as airports, railway stations, offices, factories, shopping malls, healthcare centers, etc., where the possibility of overcrowding is high.
The principle of IR thermometers is simple. Infrared radiation is emitted by all living objects. By measuring the heat due to infrared radiation on the skin, one can get an idea about the body temperature of the subject from a distance. The handheld devices, like thermal guns and other scanners, have a lens that can be focused on the subject emitting infrared radiation and transferred to a sensor, which then measures the temperature. This sensor is the vital component of the thermometer. It helps convert the radiation into an electrical signal and process the latter to give out a temperature reading. Sounds pretty simple? Well, it’s not.
What is emissivity and what does it have to do with IR thermometers?
Every object, living or otherwise, emits infrared radiation. However, some substances or surfaces emit it more readily than others. The efficiency at which every living and non-living substance emits infrared radiation is called emissivity. If you wish to know about Infrared thermometers in detail, you have to get an idea about this emissivity. According to the experts, the conventional IR thermometers can measure the temperature of objects having an emissivity of about 0.95, accurately. While most objects have their emissivity near to this, shiny or reflective surfaces may have a much lower value. Hence, the chances of getting inaccurate temperature readings are common, if you are wearing jewelry or reflective accessories, like glasses, etc.
However, one can always use thermometers having variable emissivity settings. While some of them have “high, low, or moderate” options, some others come with full-fledged adjustable emissivity settings. Hence, it is recommended to check the manufacturer’s guidelines before buying an IR thermometer. One more trick to measure temperatures accurately from shiny surfaces is to apply a non-reflective tape on it before taking the readings. But it is not always possible, especially in the pandemic situation, where a lot of people have to be scanned for fever rapidly.
Some other factors to consider for accurate readings
The IR thermometers do not work on magic. One needs to understand each component and settings before using these to enhance accuracy. Besides emissivity, one should also consider reading speed, the field of view, D:S ratio, laser targeting efficiency, and other factors as well. Let us give you a brief idea about the same.
The reading speed of an IR thermometer is essential to consider while measuring the temperature of mobile objects, or living beings. It is extremely important for scanning fever in crowded places. Hence, care should be taken to understand the reading speed of an IR thermometer before purchasing it.
Field of view is the area from which the infrared energy is focused on the lens of the thermometer’s optical system. The more the distance from the IR thermometer, the wider is the field of view. The angle at which the lens is focused also affects the field of view. For best results, it is recommended to hold the thermometer at 90 degrees from the surface to be measured. One should keep in mind that the thermometer may fail to give accurate readings if the surface does not fit into its field of view. Infrared energies from neighboring objects may affect the readings then.
The D:S ratio, also known as the distance-to-target ratio, is the next consideration on the list of factors affecting an IR thermometer’s reading accuracy. Simple thermometers may have a D:S of 1:1, which other expensive varieties can guarantee values nearing 60:1 or even higher. These are thermometers that can measure temperatures of smaller areas from a greater distance accurately.
The laser targeting efficiency of an IR thermometer can also affect its readings. While a simple laser system can target the approximate center of the field of view, a complex one can use more than two lasers to target the entire field of view and give you a more-or-less accurate reading. If the operator does not have much experience in handling IR thermometers, it is recommended to use such multiple-laser systems for higher efficacy.
External weather - A challenge yet to overcome
Not only the aforementioned factors, but several other things may affect the temperature readings. Some of these, like external weather, fog, precipitation, heat, and cold waves may alter the readings partially or completely. For example, if there are heavy snowfall and chilly winds, people with fever may show lower temperature levels and may enter a space, undetected. Similarly, if someone does not have a fever, but the climate is hot, then the surface of the skin may show elevations in temperature, which can be mistaken as fever. It is almost impossible to resolve this issue in regular IR thermometers.
So, what can be done?
Enters the OPX IR thermometer!
What it is
The OPX technology incorporated in these thermometers can rule out all possibilities of false positives or negatives due to external weather conditions. It can also render handheld thermometers obsolete for good. As it is, these thermometers cannot be used in crowded places, as it takes time to measure temperatures accurately with the devices, thus resulting in long queues. These are fast, efficient thermometers perfect for the pandemic situation. The OPX thermometers ensure the highest accuracy, as these have spatial geometric sensors along with AI algorithms to identify and obliterate effects of external weather while taking temperature readings. Further, these can also neutralize the effect of direct or indirect sunlight on the skin surface, thus giving accurate readings.
How Machine Sense can help
The FeverWarn IR thermometers developed by us at MachineSense incorporate the OPX technology to reduce the hassles of measuring temperature from a distance. The devices are simple and easy-to-use, as well as follow all FDA regulations to give accurate readings for multiple scans. You can have them anyway you want, whether you need a handheld scanner or otherwise. FeverWarn fever scanners are currently gaining huge popularity across the country because of their accuracy and inherent simplicity. If you are looking for an effective scanner to fight the pandemic and keep your people safe, you can give this one a go.