What Is a Digital Thermometer? – RespiratorsN95mask  

What Is a Digital Thermometer?

by Jason Willis

What is a digital thermometer?

Digital thermometers do not contain mercury, rather a thermistor inside the tip that helps detect body temperature. As a result, digital thermometer provides quick result with greater accuracy. Digital thermometers are becoming very popular by the day. Especially during pandemic when temperature screening at public places, schools and offices is a must, digital thermometers are very useful.

Components of digital thermometer: -

A high quality thermometer that works digitally must have following components that function optimally.

  • Battery: -

Digital thermometers are battery operated which is known as button cell. The small and silver metal battery works at a voltage of 1.5V normally. It is situated at the thermometer’s back under the cap.

  • Structure of digital thermometer: -

The structure of a thermometer is composed of a hard plastic body. Generally, it is 100.5mm in length. It gets wider in the bottom compared to the top. The tip of a digital thermometer is its thinnest part. Different parts that make up the structure of a digital thermometer include digital display, power button, circuit and other parts. The power button is pushed to switch on and off. A beep sound signifies that the thermometer has been switched off. The display screen is normally 15.5mm in length and 6.5mm in width. It shows temperature in both degrees Celsius and degrees Fahrenheit units. IT depends on what unit you set. These are the generic components however specific design can be different for different manufacturers.

  • Internal circuit of digital thermometer: -

A high quality thermometer must have an efficient and well-functioning internal circuit that gives zero error. The circuit comprises of a Microcontroller, capacitor, sensor, resistor, buzzer and a switch. The microcontroller is the main part of a digital thermometer which is embedded as COB IC. A Microcontroller converts the value of temperature recorded in analog form into digital form. Then the value is displayed on the screen. There is a higher limit to the temperature that can be detected. If the temperature is greater than this value it is indicated by a sound made by the buzzer.

How does a digital thermometer work?

The tip of a thermometer is placed near the person’s body part usually forehead, whose temperature has to be detected. The thermistor which is a ceramic semi-conductor inside the tip of thermometer measures the temperature. A cap covering prevents it from getting in contact with outer world; maintaining its required sensitivity to temperature changes.

Benefits of digital thermometer: -

Digital thermometers are making mercury thermometers obsolete. IT is because of the wide range of benefits it provides. Here are some of them.

  • Greater accuracy: -

A mercury temperature tends to measure the surface temperature such as that of armpit or mouth giving fluctuating readings. On the contrary, a digital thermometer accurately measures the overall body temperature. This helps in better diagnosis leading to better treatment.

  • Faster results: -

Measuring temperature with a mercury thermometer requires you to wait for two minutes to reach the recording. On the other hand, digital thermometer gives accurate result in just about three seconds. To record another body’s temperature, you have to shake the mercury thermometer rigorously so that it can go back to original level. That is not the case with digital thermometer. You can measure next body temperature instantly after it has recorded one.

  • Memory function: -

A digital thermometer allows you to maintain a log of body temperature at various points in time. Such data is very important to analyze a patient’s progress and treatment.

  • Easy to carry: -

Glass body of mercury temperature makes it a dangerous object especially for children. If broken, thermometer can be too dangerous as it has mercury inside. On the other hand, digital thermometer is quite safe as well as easy to carry.

  • Easy to interpret: -

Small print on a mercury thermometer often makes it difficult to read the temperature. This is not the case with digital thermometer as it gives the reading that can be read instantly without any effort.

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