Digital vs Infrared Thermometer: What’s The Difference?

Digital vs Infrared Thermometer: What’s The Difference?

Written by Alison Lurie, In Technology, Published On
June 7, 2022

Thermometers have been in use for hundreds of years, with the very first invented in 1612 for taking air temperature. It has been through radical changes since then, and now there are a variety of thermometers available for different uses.

The traditional thermometer has been rendered almost obsolete now that digital thermometers are affordable. And the newest thermometer on the market is the infrared thermometer. It is a non-contact option that comes in medical, food, and industrial options. And digital thermometers may find themselves obsolete. But, what is the difference between digital and infrared thermometers?

Digital vs Infrared Thermometer: What’s The Difference?

  • Digital

Digital thermometers are most commonly used in a medical setting – they determine body temperature through heat sensors. They can be used in the armpit, mouth, or rectum. The armpit temperature reading is around 0.6°C cooler, while the rectal reading is 0.6°C warmer.

The greatest benefit of a digital thermometer, aside from its accuracy, is that it provides a reading in around a minute or less.

As with any product, there are drawbacks to using digital thermometers. Rectal readings are considered the most accurate temperature measurements, which isn’t the most convenient option, especially when dealing with small children. Oral readings are impacted by recent eating and drinking. If switching between oral and rectal readings, two thermometers should be kept and clearly labelled. It is necessary to replace batteries periodically.

A digital ear thermometer relies on infrared technology to read the body’s temperature via the ear canal. It offers a quick and accurate reading and is more comfortable than a rectal or even oral thermometer. Unfortunately, they are not suitable for babies younger than six months. And earwax can present an obstruction that skews the result.

  • Infrared

Infrared thermometers read from a distance, they do not need to make contact with the item they are reading. This is true whether it’s a human temperature or an industrial reading of a circuit board. The reading provided by an infrared thermometer isn’t impacted by drinking, eating or ambient temperature. It will provide a highly accurate reading if the manufacturer’s instructions are followed properly. You can have a result within seconds when you opt for an infrared thermometer.

A forehead thermometer uses infrared sensors to provide a digital result – it does the job by measuring the superficial temporal artery’s temperature. It’s a no-contact option that is commonly seen in airports, stadiums, and stores following COVID-19. The results are around 0.6°C cooler than an oral temperature. It can produce a result within seconds and is easy to administer, but positioning is key to accurate results. There are external factors, such as sunlight, heating, wind, and drafts that impact readings. Certain clothing can also skew results. So, while infrared thermometers produce accurate results quickly, they aren’t as accurate in the medical field as a digital thermometer may be.

Final thoughts

Whatever thermometer you use, the instructions provided by the manufacturer should be followed. Ultimately, no matter how accurate or expensive a thermometer is, it will not produce accurate results if it isn’t used correctly.

Every thermometer is made with an express purpose, a medical thermometer should be used in that setting, and an industrial thermometer isn’t a suitable alternative. Typically, digital thermometers are used in a medical setting, whereas infrared thermometers are more likely to be used in industrial settings.

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