THERMOMETER
The thermometer is used as an “instrument for measuring temperature.” “Thermo” is a prefix related to heat, and “meter” is a suffix used for any measuring device.
What is a normal body temperature?
The normal body temperature is about 98.6 degrees in Fahrenheit (° F) or 37 degrees in Celsius (° C). Normal body temperature is usually lower in the morning and higher during the day. It reaches its peak in the late afternoon or in the evening.
Primary and secondary thermometers
Depending on how the measured gross physical quantity is assigned to the temperature, the thermometer is called primary or secondary. “For the primary thermometers, the measurement properties of the matter are well known, so that the temperature can be calculated without unknowns. For example, the thermometer based on the equation of state of a gas, the speed of sound in a gas , thermodynamics, noise voltage or current of a resistance, and the angular anisotropy of gamma rays emitted by certain radionuclides in a magnetic field .
Secondary thermometers are the most widely used due to their convenience. Furthermore, they are generally much more sensitive than primary thermometers. For secondary thermometer, knowledge of a measurement properties is not sufficient to directly calculate the temperature. They should be calibrated to at least one set temperature or multiple temperatures using a primary thermometer. Such fixed points, such as the triple point and superconducting transition, can occur repeatedly at the same temperature.
Traditional thermometer
Traditional thermometers are non-register thermometers. In other words, after the thermometer is moved to a different temperature, the temperature reading is not maintained. Determining the temperature of a pot of hot liquid requires the user to leave the thermometer in the hot liquid until after the reading. If an unregistered thermometer is pulled out of the hot liquid, the temperature indicated on the thermometer will immediately begin to change to reflect its new condition temperature (in this case, air temperature). The recording thermometer is designed to hold the temperature indefinitely so the thermometer can be removed and read later or in a more convenient location. The mechanical recording thermometer maintains the highest or lowest recorded temperature until it is manually reset, for example by shaking the mercury glass thermometer, or until a more extreme temperature is experienced. Generally the electronic recording thermometer can be designed to recall the highest or lowest temperature, or to recall any temperature that has occurred at a specific point in time.
Thermometers are increasingly using electronic means to provide digital displays or inputs to computers.
What Are the Different Types of Thermometers?
Not every thermometer is made in the same way, the following types are the different types of thermometer:
- Digital
- Mercury/Alcohol
- Liquid Crystal
- Meat/Food Thermometer
Digital thermometer
Digital thermometers are the most common type of thermometer and are considered the safest. It is either a traditional stick or contains a probe at the end that can be scanned on the forehead. Either way, the temperature will be displayed on an easy-to-read display.
A simple digital thermometer is a combination of a thermocouple, a battery-powered dual-slope digital voltmeter (used to measure the output of the thermocouple), and an electronic display. It provides a low-noise digital output that can resolve temperature differences as small as 0.1°C. The accuracy achieved depends on the accuracy of the thermocouple element, but the measurement error can be reduced to ± 0 5%.
features of digital thermometers:
- Digital thermometers rely on metal and electrical probes to function.
- Since the numbers are displayed on the screen, you can easily read the temperature. The
- Digital Thermometer provides faster results than mercury thermometers.
- Recommends that you use a digital thermometer to measure the temperature of children or babies, because they are safer to use.
Mercury/Alcohol Thermometer
The first mercury thermometer was invented in 1714. Basically mercury is a dense and toxic metal, so that the Environmental Protection Agency (EPA) recommends that you handle these thermometers with care.
In a mercury thermometer, the glass tube is filled with the mercury, and the tube is marked with a standard temperature scale. As the temperature changes, the mercury expands and contracts, and the temperature can be read on the scale. Mercury thermometers can be used to determine body temperature, liquid and vapour temperature. Mercury thermometers are used in households, laboratory experiments, and the industrial applications.
features of mercury thermometers:
- Mercury thermometers are based on the natural chemical reaction between mercury and hot or cold temperature.
- You can read the temperature by checking where the bar falls on the line. The largest line is 1 ° F and the smallest line is 0.2 ° F.
- The Mercury Thermometer can withstand boiling and freezing temperatures, while the Digital Thermometer can be damaged in extreme conditions.
- It is dangerous if the mercury thermometer breaks on the ground, because mercury is poisonous.
Liquid Crystal thermometer
Liquid crystal thermometer is a tool for measuring temperature range and heat transfer mode. The result is shown by the color change of the cholesteric liquid material made into the liquid crystal thermometer. These thermometers are used in a variety of applications, from reading patient temperature to accurately measuring air and liquid temperature ranges in chemical laboratories or breweries. The low cost of this instrument, coupled with its ability to accurately measure a wide range of temperatures, makes this thermometer an indispensable part of many medical and manufacturing processes.
As the room temperature rises and falls, the color of the cholesterol-based liquid in the entire strip changes. To read the LCD thermometer, the user only needs to pay attention to the color change of the thermometer. In some cases, the thermometer is also marked with temperature and digital names to improve the accuracy of the readings.
Liquid crystal thermometers are generally used as equipment for home brewing of alcoholic beverages or other chemical reactions that require temperature adjustment. One of the most common types of thermometers in use today is duct tape, which adheres to the outside surface of a bottle or laboratory equipment and produces accurate readings of the temperature of the container. For micro-brewing and other operations, the thermometer can accurately measure the temperature range in the brewing vessel. Although the measurement is not as accurate as laser thermometers or traditional liquid-immersed thermometers, the results produced by liquid crystal thermometers are accurate enough for reactions that must be kept within a certain temperature range, rather than a specific target temperature.
In a laboratory setting, liquid crystal thermometers can be used to measure temperature changes and transmission modes. The cholesterol-based liquid in the thermometer can be used to effectively track heat transfer through convection, radiation, and conduction. By heating the thermometer and then tracking the rate of evaporation or immersion of the liquid to reduce the temperature of the thermometer, the same principle can also be used to test the cooling characteristics of the liquid.
Meat/Food Thermometer
You can buy a special thermometer for cooking! The food thermometer is inserted directly into the meat to ensure that the internal temperature is fully cooked.
Cooking food to the required internal temperature ensures that you will not eat dangerous bacteria. When you want to know whether the required internal temperature has been reached, you need a food thermometer.
According to the U.S. Food and Drug Administration (FDA), the following should be the minimum internal temperature for meat:
Beef: 140°F
Pork: 145°F
Poultry: 165°F
Fish: 145°F
What Are the Different Ways a Thermometer Can Be Used?
The thermometer is designed to measure body temperature in many different ways. In fact, some thermometers are designed for certain parts of the body.
- Axillary thermometer (under the arm)
- Oral thermometer (under the tongue)
- Tympanic thermometer (in the ear)
- Rectal thermometer (in the rectum)
- Infrared or temporal artery thermometer (above the forehead)
Axillary Thermometer
For this method, a thermometer is placed in the armpit for use by young children or adults who cannot safely measure body temperature through their mouth. This method is not as accurate as the oral or rectal method, but can be used as a quick first check.
Oral Thermometer
For this method, the thermometer is placed under the tongue. This method is suitable for adults and children 4 years and older who can hold a thermometer in their mouth.
Tympanic Thermometer
This type of thermometer measures the temperature in the ear by reading the infrared heat in the ear. For best results, be sure to follow the device’s instructions for proper tip placement. For babies and older children, ear thermometers can be used faster and easier. However, if your baby is less than three months old, they are not recommended. If your child has excess earwax or earaches, they should not be used.
Rectal Thermometer
It can be difficult to take the temperature of younger children since they don’t sit still, so that rectal thermometer is a good solution and is often recommended for infants.
Temporal Artery Thermometer
In recent years, infrared or temporal artery thermometers have become very popular. This type of thermometer is very comfortable to use and one of the most comfortable options.
Forehead thermometers are also used to measure temperature, but they may not be as reliable as digital thermometers and are usually more expensive. They are placed in the temporal artery of the forehead and measure the infrared heat emitted from the head.
Which Type of Thermometer is Most Accurate?
Using an oral thermometer will give you the most accurate results. Make sure to place the thermometer under your tongue and keep your mouth tightly closed.
If you are using a digital thermometer, it is also important to keep the thermometer in place for at least 30 seconds. You should avoid eating or drinking for at least 20 minutes before taking your temperature for best results.
Can I Use a Food Thermometer to Check My Body Temperature?
If things get complicated, you can use a meat thermometer to measure your body temperature. It is definitely not as accurate as a medical or clinical thermometer, but it will work when necessary. The Coronavirus (COVID19) pandemic has caused a severe shortage of digital and mercury thermometers in stores across the country. Meat thermometers became a good substitute during the crisis. If you use this method, be sure to place the thermometer under your tongue and keep it still. If you have a high fever, contact your doctor as soon as possible.
Can a Smartphone Be Used as a Thermometer?
Do you need to take your temperature? There is an app! You will find options to track fever on Android and iPhone.
The following apps will measure your body temperature and can be used on Android and iPhone:
Fingerprint Thermometer
- iThermonitor
- Real Thermometer
- Smart Thermometer
- Vick’s SmartTemp
- Thermometer ++
- EasyBBQ
- iCelsius
This is not an exhaustive list, but these apps are the most popular. They work through a digital scanner, which reads your temperature when you place your index finger on the screen.
Please note that these applications may not be as accurate as glass or electronic scanners, so proceed at your own discretion. When in doubt, it is best to use a doctor-approved thermometer to measure your body temperature.
If Your Mercury Thermometer Breaks then what do you do?
If your mercury thermometer gets break, don’t panic. The Environmental Protection Agency (EPA) has created these easy-to-follow tips to make you safe:
- Immediately Get your kids and pets out of the room
- You should open up the window and leave it open for at least 15 minutes
- You must wear rubber gloves and old clothes to clean up the mercury beads and glass.
- You should Collect the mercury beads with an eyedropper. Note: You should not use a broom or vacuum.
- You can use torch lights to make sure that you have found all the beads.
- If you still see small beads, put shaving cream on top of a paintbrush and then you can “dot” the affected area. You can then use the duct tape to grab those tiny beads.
- You should Wipe the affected area with a damp cloth, making sure to get every inch
- You should Put the beads, your gloves, the duct tape, the eyedropper, and the cloth inside of a garbage bag. Tie the bag carefully and securely closed.
- Then you can Contact your local health or fire department to find out how to properly dispose of the bag.
- Make sure to Let the room ventilate for the next 24 hours
Do Thermometers Expire?
The thermometer will not expire, but will eventually need to be replaced. Digital thermometers will last 3-5 years, while mercury thermometers will be used indefinitely as long as they are not broken or damaged.
Has your mercury thermometer stopped working? Put it in the fridge or freezer. The cold will cause the mercury to vibrate a bit, which may fix the problem. If not, it may be time to look for alternatives.
Can You Recycle a Thermometer?
Thermometers are considered hazardous waste and which are cannot be recycled. Your best option is to wait for your community to host a hazardous waste collection day or find a facility near you. If possible, please avoid throwing hazardous waste into the trash can. This includes not only thermometers, but also for the lighters, pesticides, paint, batteries, and electronic products such as mobile phones and TVs.
Conclusion
The thermometer is a great invention! You can easily check for a fever, and you can do this in a number of ways. Your health should always be the number one priority, so make sure you always have a working thermometer in your home.
