While non-contact infrared thermometers were originally used in industrial applications such as manufacturing to fire fighting, its commercial use for detecting human body temperature is fairly recent.
In 2003, some Asian airports used non-contact infrared thermometers to screen passengers for Severe Acute Respiratory Syndrome, or SARS. In 2009, World Health Organization (WHO) suggested that airports should check temperature of travellers and look for symptoms of H1N1 flu.
Later in 2014, health officials worldwide deployed non-contact thermometers to detect Ebola symptoms. The no-contact thermometer was thus getting extensively used in airports in Africa and Asia and later in the US. Recently, with the outbreak of novel Coronavirus, you can see on television and media that airport officials are using these hand held devices on forehead of air passengers to make a quick check on fever symptoms.
The hand-held, no-touch thermometer thus has emerged as a popular choice for detecting fever quickly and easily. You will find this also to be a non-invasive, accurate and relatively inexpensive and it also minimizes risk of spreading infections.
A strong body immunity can fight any kind of viral or bacterial infection.
How do non-contact digital thermometers work?
The non-contact infrared thermometer is a novel way of measuring your body temperature in a simple way. With this device, you can take measurement in just 2 seconds.
The thermometer tells how hot a person’s body is by measuring the infrared energy coming off the body. Human skin is a very good emitter of infrared energy and this helps in detecting body temperature, typically forehead.
The non-contact thermometer consists of a lens to narrowly focus the infrared (IR) energy coming off human body on to a detector in the device. The device then converts this heat energy to an electrical signal. The electric signal is then shown as units of temperature in Fahrenheit or Centigrade degree scales on thermometer’s display screen. Usually, devices are built to compensate for any environment or surrounding temperature variations.
Infrared thermometers are today’s new age device which facilitates temperature measurement from a distance without any contact with the person or object to be measured. This is what makes it a super convenient and smart in many unique circumstances.
Difference between human thermometer and industrial one
It is necessary that the device should read temperate of human body (typically the forehead area) and NOT record temperature of surrounding areas such as wall, chair or hair etc.
This is achieved by way of making a narrow field of view for the device. The device sensor uses a silicon lens to focus infrared energy on a precise point of human body such as forehead. In this way human non-contact thermometer is different from an industrial one which may cover a broader area of the object.
Another difference is that the human thermometer has a built-in logic for translating sensor energy readings to equivalent oral readings of a normal thermometer. In this manner, you get a correlated body temperature to detect fever conditions. This logic is based on empirical data collected from past medical studies.
What is accuracy level of non-contact infrared thermometers?
Experts suggest that readings of forehead temperature are close enough match for the purpose of screening for fever conditions. You may be familiar with traditional way of quickly checking your body temperature when your mother puts her hands on your forehead. The principle behind this device is also similar.
Studies say that under-arm or armpit (axillary) temperature is usually 0.5°F (0.3°C) to 1°F (0.6°C) lower than oral temperature. A forehead (temporal) scanner is usually 0.5°F (0.3°C) to 1°F (0.6°C) lower than an oral temperature. Hence, a good non-contact thermometer should match an oral thermometer typically within two-tenths of a degree (i.e. 0.2 °C).
Research has shown that the infrared digital non-contact thermometers are reliable, convenient and accurate alternatives for measurement of temperature. They are hugely popular and useful for screening of fever in the paediatric (children) population as well.
A NCBI (US) study compared the performance of non-contact infrared thermometer against mercury-in-glass thermometer in children. It concluded that infrared non-contact thermometer is a quick and non-invasive method for temperature recording in children.
What are advantages of non-contact thermometers ?
Non-contact thermometers can allow you to make accurate temperature measurements that are completely trustworthy. Since you do not make contact, you can take measurements even when your baby is asleep, without your child even realizing.
You may have already noticed these infrared non-contact thermometers being used at airports to check arriving travellers for fever, viral conditions or infection disease such as Coronavirus causing fever. Most common infrared thermometers are spot infrared thermometer type that measures the temperature at a spot on a surface.
Hence non-contact thermometers are very reliable and convenient solution for babies and restless children who are too impatient to allow for sustained temperature reading with a normal mercury or digital thermometer.
Secondly, you will find this useful for adults and very old people as well, especially bed ridden or restless seniors who may find it difficult to maintain steady posture for a thermometer reading.
Lastly, you can safely use no-contact thermometers in situations where you do not want transmission of any infection.
For all the above reasons, the infrared thermometers are getting increasingly used at homes and in hospitals for checking fever in children or old bed ridden patients without touching them or distracting them.
Check out the following curated infrared thermometers
What are other home uses of non-contact infrared thermometers?
You can use some of the normal human infrared thermometers, depending upon their specifications & temperature range, for checking heater or oven temperature or how hot your cooked food is.
Measurements can be taken from a distance for hot objects and surfaces for cooking or food service purposes. You would like to know how hot your food is for controlling temperature during cooking or before serving such hot food to children or very old seniors.
This is also useful when you can’t or should not touch the items, or items may contaminate on touching.
You can use these infrared thermometers for taking temperature of a variety of household and work objects. Get this device and measure temperature of stews, puddings, soups and anything!
Industrial Infrared thermometers – Uses
At a broad level, the infrared thermometers fall into a class of industrial devices known as thermal radiation thermometers. By knowing the amount of the infrared or heat energy emitted by the object, the object’s temperature can be determined.
Industrial grade infrared thermometers have been getting used in many manufacturing, fire-fighting and geological applications since a long time. They are useful in circumstances where the object to be measured is moving or is surrounded by an electromagnetic field, as in case of induction heating or other controlled atmospheres. Infrared thermometer is installed in a large range of process applications including metals, minerals, the paper and the plastics.
They are also used in detecting clouds for remote telescope operation, checking mechanical or electrical equipment for the temperature and hot spots, checking for hot spots in fire-fighting, monitoring materials in the processes involving heating or cooling and even measuring temperature of volcanoes.
What are disadvantages of Infrared thermometers ?
Infrared non-contact thermometers can be temporarily affected by drastic changes in environment or room temperature. In these conditions, readings may be subject to some error due to mixing with reflection of heat from a hotter or colder body.
For instance, if someone is sweating or has been in front of a fan or just taken a bath, the forehead skin has become cooler. In these cases temperature readings may be inaccurate (i.e. lower). But this is true for for any thermometer!
Hence, this type of fever detector is most accurate when measuring temperature of dry skin in a breeze-free room.
Secondly, the readings may also be affected by closeness to any radio signals or electromagnetic field (if strength is 3 volts per meter or more).
How to use a non-contact infrared thermometers
You will have to take into account certain factors to be able to use this new technology device called non-contact thermometers well, or infrared thermometers.
Non-contact infrared thermometers can be affected by conditions in the external environment. Hence, after you buy a non-contact thermometer, you should spend a few minutes learning how to use it. Just follow the tips given below and you will do absolutely fine with this device!
- Check that the infrared sensor is clean before using. You should not touch or blow air on the infrared sensor, as a dirty sensor can lead to erroneous measurements
- After taking out the thermometer, allow 5-10 minutes for the thermometer to adjust itself with the room temperature.
- You should not expose this thermometer to extreme temperature conditions of 50°C or 20°C (122°F or -4°F).
- Ensure that very high or very low ambient temperatures are not present while using the thermometer. This can happen, in situations of cooking in case of adults or snuggling or breastfeeding in the case of babies. Similarly, very cold temperatures can happen outside in winter or just after bathing in summer. These situations can affect the temperature readings of the forehead.
- You should carefully point the thermometer at person’s forehead at a distance of 5 cm or so, and then press scan or start button of the device for about a second or two. And it is done!
The hand-held, non-contact thermometer has emerged as a good high-tech choice for detecting fever quickly. You will find this device to be easy to use, non-invasive, accurate, infection-free and relatively inexpensive. Use this infrared thermometer at home for checking fever in your children or very old seniors without touching them or distracting them. You can even use this device for controlling temperature of household food items during cooking or before serving to kids and old people, or help in your fine controlled temperature cooking!