Thermometer

Thermometer

A device that lets one know the temperature of their body. The most simple kind of thermometer is the one that has mercury inside. The bulb end is placed under the tongue or inside one's armpit. The mercury moves along a very fine tube when there are changes in temperature. The tube has markings along it that let one know the temperature based on how much the mercury has expanded.

One needs to vigorously swing a mercury-based thermometer to 'reset' it, this was considered to be problematic as the thermometer can slip. This leads to the glass casing breaking. As mercury is a toxic substance to avoid this today many other kinds of thermometers are used.

Digital Thermometer

Today digital kinds of thermometers are quite common. These display the temperature on a small LCD screen. There are a few different ones, one is designed to function similar to the mercury thermometer and is either placed under the tongue or inside the armpit.

Tympanic Thermometer

Another sort is the thermometer that takes temperature from one's ear, it is known as a tympanic thermometer. This has a small bauble that is held gently inside the ear and emits infrared to take a reading. The idea behind this kind was to take a temperature closer from the brain; specifically from the hypothalamus as it regulates the body's temperature. These can be a bit unreliable if it is not held in the correct position or if there is wax, giving a lower reading.

Infrared Thermometer

There are also infrared thermometers that take a reading from the temporal artery. This is preferred as it has minimal invasiveness in comparison to the others. This device is pointed towards a patient's forehead and gives a reading. This kind may also have some issues with precision but lesser issues with accuracy. They are considered to have an accuracy of about 60-70% but are highly specific at 97-100% in detecting fevers or hypothermia. 

Pacifier Thermometer

For babies one can find a digital thermometer that is made similarly to a pacifier, these are also called pacifier thermometers. This is used as babies tend to not sit still, making it difficult to get their temperature with regular thermometers.

The basal thermometer

The basal temperature of the body is the temperature at the time of waking up, this is not affected by food intake or movement and exercise. These kinds of thermometers are based on the same principles as the others but have a higher number of marks or read points. A regular thermometer will have readings that will show 0.1 Celcius; basal thermometer will have more decimal places visible such as 0.05 Celcius. Giving a detailed and accurate reading of smaller changes.

Digital basal thermometers may have a larger screen, memory functions and beeping to let you know it has been placed correctly.

Smart thermometer

A lot of the wearables today such as smart bands/bracelets and smartwatches have the ability to take one's temperature and can also log it over a time period. There is the slight drawback that these wearables cannot provide the core body temperature as they are worn on the surface.

Accuracy of digital thermometers

The accuracy of digital thermometers has been questioned at times. The stated level of accuracy varies but is somewhere within ±0.2 °C (±0.35 °F) when new. If one does regular recalibrations it can be kept within a minimal range of inaccuracy.

For more accurate study many medical professionals still rely on mercury thermometers instead of the digital variants, as they are not yet advanced enough to be dead right along with the convenience of speed.

Comments

A mercury thermometer can be found from many makers with some that are near nameless. It will also be the cheapest option to purchase.

Known brands that produce digital thermometers include Mothercare and Beurer. The price varies depending on what specific kind of thermometer it is and the brand that produced it. Prices can range from mid-range to the top of the price spectrum.