Which type of thermometer is the most accurate?
Digital thermometersDigital thermometers are the most accurate way to measure body temperature. There are many types, including oral, rectal, and forehead, plus many that are multifunctional. Once you decide on the type of thermometer you want, you can think about design, extra features, and price.
Which thermometer is best for Covid 19?
No-touch or non-contact infrared thermometers measure temperature through the forehead from a close distance in seconds. They may be used on newborns and older people. They're easy to use and may reduce the risk of spreading disease by allowing more physical distancing.
What is the best fever thermometer for adults?
A quick look at the best thermometersBest overall thermometer: CHOOSEEN Digital Forehead and Ear Thermometer 8-in-1.Best ear thermometer: Braun Thermoscan 7.Best oral thermometer: Vicks ComfortFlex Thermometer.Best forehead thermometer: Exergen Temporal Artery Thermometer.More items...
What are the 3 types of thermometers?
There are different types, but not all thermometers are right for your child.Digital thermometers. ... Ear (or tympanic) thermometers. ... Infared thermometers. ... Strip-type thermometers. ... Mercury thermometers.
What thermometer do doctors recommend?
What are the best thermometers? Of all the thermometers we considered, for most people we can recommend the iProven DMT-489, a dual-mode infrared thermometer that takes fast, accurate readings from either the forehead or the ear.
How reliable are forehead thermometers?
How accurate are they? For general use at home, forehead thermometers will give an idea of whether or not an individual has a fever. However, according to a 2020 study, forehead thermometers are less accurate than other methods of reading temperature, such as oral, rectal, or tympanic (ear) temperature readings.
What thermometers do hospitals use?
Hospital thermometers such as TRITEMP™ use sophisticated TAP&TAKE technology, meaning that the healthcare professional simply aims the device at the patient's forehead, and receives an accurate core body temperature reading in seconds.
How do I check my temperature with my phone?
1:464:56And this is basically the sensor here wherein you need to put in your finger on this and only thisMoreAnd this is basically the sensor here wherein you need to put in your finger on this and only this finger right so in this hand this finger if you put it here you can see this will start vibrating.
Which forehead thermometer is the most accurate?
The Braun Digital No-Touch Forehead Thermometer was by far the best we tested. This thermometer guides you through the entire temperature-taking process with directions conveniently printed right on the front of the thermometer.
Are No Touch thermometers accurate?
Research has shown that, when used correctly, infrared or no-contact thermometers are just as accurate as oral or rectal thermometers. No-contact thermometers are popular among pediatricians, as kids often squirm around when trying to get a temperature read, but it also holds true in mass temperature screenings.
What are the 7 types of thermometer?
7 Types of Thermometers and to what Degree You Should Trust ThemForehead strips. ... Wearable thermometers. ... Pacifier thermometers. ... Ear thermometers (tympanic) ... Forehead thermometers (temporal) ... Digital thermometers. ... Non-contact Infrared Thermometers. ... Bonus: Mom's hand or lips.More items...•
Which is more accurate mercury or digital thermometer?
Digital thermometers provide better accuracy In fact, some digital thermometers also include thermocouple sensors on the probe that have been measured and calculated to provide very high accuracy and without the need for calibration like mercury thermostats.
How to measure temperature with a thermometer?
The traditional way of putting a scale on a liquid-in-glass or liquid-in-metal thermometer was in three stages: 1 Immerse the sensing portion in a stirred mixture of pure ice and water at atmospheric pressure and mark the point indicated when it had come to thermal equilibrium. 2 Immerse the sensing portion in a steam bath at Standard atmospheric pressure and again mark the point indicated. 3 Divide the distance between these marks into equal portions according to the temperature scale being used.
What is a thermometer called?
A thermometer is called primary or secondary based on how the raw physical quantity it measures is mapped to a temperature. As summarized by Kauppinen et al., "For primary thermometers the measured property of matter is known so well that temperature can be calculated without any unknown quantities. Examples of these are thermometers based on the equation of state of a gas, on the velocity of sound in a gas, on the thermal noise voltage or current of an electrical resistor, and on the angular anisotropy of gamma ray emission of certain radioactive nuclei in a magnetic field ."
Why are thermometers important?
Thermometers are important in food safety, where food at temperatures within 41 and 135 °F (5 and 57 °C) can be prone to potentially harmful levels of bacterial growth after several hours which could lead to foodborne illness. This includes monitoring refrigeration temperatures and maintaining temperatures in foods being served under heat lamps or hot water baths. Cooking thermometers are important for determining if a food is properly cooked. In particular meat thermometers are used to aid in cooking meat to a safe internal temperature while preventing over cooking. They are commonly found using either a bimetallic coil, or a thermocouple or thermistor with a digital readout. Candy thermometers are used to aid in achieving a specific water content in a sugar solution based on its boiling temperature.
When was the thermometer invented?
The first clear diagram of a thermoscope was published in 1617 by Giuseppe Biancani (1566 – 1624): the first showing a scale and thus constituting a thermometer was Santorio Santorio in 1625. This was a vertical tube, closed by a bulb of air at the top, with the lower end opening into a vessel of water.
What is mercury thermometer?
Mercury thermometer (mercury-in-glass thermometer) for measurement of room temperature. An alcohol thermometer for measurement of outdoor temperature. A thermometer is a device that measures temperature or a temperature gradient (the degree of hotness or coldness of an object). A thermometer has two important elements: (1) a temperature sensor ...
What is the purpose of a Galileo thermometer?
Galileo thermometers are used to measure indoor air temperature, due to their limited measurement range. Such liquid crystal thermometers (which use thermochromic liquid crystals) are also used in mood rings and used to measure the temperature of water in fish tanks.
Where did the word "thermometer" come from?
The word thermometer (in its French form) first appeared in 1624 in La Récréation Mathématique by J. Leurechon, who describes one with a scale of 8 degrees. The word comes from the Greek words θερμός, thermos, meaning "hot" and μέτρον, metron, meaning "measure".
What is the purpose of a digital thermometer?
Digital thermometers use a thermistor, a resistor with a resistance that varies with temperature. To measure body temperature, infrared thermometers that focus infrared light onto a detector that measures the amount of light received and convert the electrical signal produced by the detector into a temperature were also used.
What is the Celsius temperature scale?
In 1848 the British physicist William Thomson (later Lord Kelvin) proposed a system that used the degree Celsius but was keyed to absolute zero (−273.15 °C); the unit of this scale is now known as the kelvin.
What temperature is the melting point of ice?
The German physicist Daniel Gabriel Fahrenheit in 1700–30 produced accurate mercury thermometers calibrated to a standard scale that ranged from 32°, the melting point of ice, to 96° for body temperature.
What is the technique used to map temperature?
Temperatures can also be mapped, using a technique called thermography that provides a graphic or visual representation of the temperature conditions on the surface of an object or land area. The Editors of Encyclopaedia Britannica This article was most recently revised and updated by Erik Gregersen, Senior Editor.
What is the effect of heating two strips?
When heated, the two strips expand at different rates, resulting in a bending effect that is used to measure the temperature change. Thermostats formerly used bimetallic strips as temperature sensors, but modern digital thermostats use thermistors.
What temperature do you take with a digital thermometer?
When assessing digital thermometer readings, keep in mind that armpit (axillary) temperature runs about ½ to 1°F (0.6°C) cooler than oral readings. Rectal thermometers run ½ to 1°F (0.6°C) warmer than oral readings.
How to use a thermometer with a sound?
Slip the plastic sheath over the bottom tip of the thermometer. The thermometer will indicate that it’s ready to be used with a sound, light, or both. Place the thermometer’s tip underneath the tongue . Some thermometers come with grooves that indicate how far into the mouth it should go.
How accurate are temporal thermometers?
Some research indicates that temporal thermometers may be as accurate as rectal thermometers in children , and provide better readings than ear or armpit thermometers can.
What is the difference between a tympanic thermometer and a rectal thermometer?
Always keep in mind that temperature readings vary, based on how the thermometer is administered: Rectal thermometer readings will be around 0.5°F (0.3°C) to 1°F (0.6°C) higher than oral temperature readings. Tympanic thermometer readings are typically 0.5°F (0.3°C) to 1°F (0.6°C) higher than oral temperature readings.
How long should you wait to take a rectal thermometer?
Wait at least 15 minutes. Rectal readings may be uncomfortable to get for infants and small children. You shouldn’t use the same thermometer for both rectal and oral readings. This may require the purchase of two thermometers, which should be labeled. Batteries in thermometers should be replaced periodically.
What are the drawbacks of a forehead thermometer?
Forehead thermometers must be positioned accurately and according to the manufacturer’s instructions, or they will not provide the right reading. Readings can be affected by external factors, including drafts, wind, indoor heating, and direct sunlight.
What is the average temperature of mercury?
The average oral temperature reading is 98.6°F (37°C). However, any oral temperature from 97°F (36.1°C) to 99°F (37.2°C) is considered typical. Some people run naturally cool, and others slightly warmer.
Types of thermometer
First things first! Before buying, you need to understand a little more about the different types of thermometer available.
Thermometer considerations
These are some of the main points to think about when selecting a thermometer for your household.
Thermometer prices
Thermometers can vary significantly in price, and the cost generally depends on which type of thermometer you choose.
1. Mercury Thermometer
A mercury thermometer is a thermometer that uses mercury as a filler. When the hot temperature is absorbed by the mercury, the mercury will expand and begin to rise to a point that indicates the temperature of the object.
2. Alcohol Thermometer
This thermometer is similar to a mercury thermometer, except that the filler in this thermometer is alcohol. Alcohols are more sensitive to temperature changes so that their volume can be clearly seen when reading the measurement results. In addition, this thermometer is safer than the mercury thermometer.
3. Mechanical Bimetal Thermometer
A mechanical bimetal thermometer is a thermometer that takes advantage of the properties of two metals with different coefficients of expansion. As the name implies, bi means two and metal means metal.
4. Digital Thermometer
A digital thermometer is a thermometer that is generally used to measure a person’s body temperature by tucking it in the armpit or in the mouth. This thermometer is made of plastic and is shaped like stationery. This thermometer uses an electronic sensor to detect body temperature.
5. Infrared Thermometer
An infrared thermometer is a thermometer for measuring the temperature of a certain object or body part without touching the object because it uses infrared or laser light.
6. Probe Thermometer
The probe thermometer is a thermometer that has a tapered sensor tip that is connected by a long cable. The pointed tip is what serves to detect heat. This thermometer is generally used in the health, laboratory, retail, and food fields by dipping the tip of the thermometer to the object. The cable is long enough to allow flexibility in its use.
7. Wall Thermometer
As the name suggests, this thermometer is hung on the wall of the room. Wall thermometer works to measure room temperature which is usually made of wood equipped with capillary pipes filled with mercury or alcohol.
Overview
Primary and secondary thermometers
A thermometer is called primary or secondary based on how the raw physical quantity it measures is mapped to a temperature. As summarized by Kauppinen et al., "For primary thermometers the measured property of matter is known so well that temperature can be calculated without any unknown quantities. Examples of these are thermometers based on the equation of state of a gas, on the velocity of sound in a gas, on the thermal noise voltage or current of an electrical resistor, an…
History
While an individual thermometer is able to measure degrees of hotness, the readings on two thermometers cannot be compared unless they conform to an agreed scale. Today there is an absolute thermodynamic temperature scale. Internationally agreed temperature scales are designed to approximate this closely, based on fixed points and interpolating thermometers. The most rece…
Registering
Traditional thermometers were all non-registering thermometers. That is, the thermometer did not hold the temperature reading after it was moved to a place with a different temperature. Determining the temperature of a pot of hot liquid required the user to leave the thermometer in the hot liquid until after reading it. If the non-registering thermometer was removed from the hot liquid, then the temperature indicated on the thermometer would immediately begin changing to …
Physical principles of thermometry
Thermometers may be described as empirical or absolute. Absolute thermometers are calibrated numerically by the thermodynamic absolute temperature scale. Empirical thermometers are not in general necessarily in exact agreement with absolute thermometers as to their numerical scale readings, but to qualify as thermometers at all they must agree with absolute t…
Calibration
Thermometers can be calibrated either by comparing them with other calibrated thermometers or by checking them against known fixed points on the temperature scale. The best known of these fixed points are the melting and boiling points of pure water. (Note that the boiling point of water varies with pressure, so this must be controlled.)
Precision, accuracy, and reproducibility
The precision or resolution of a thermometer is simply to what fraction of a degree it is possible to make a reading. For high temperature work it may only be possible to measure to the nearest 10 °C or more. Clinical thermometers and many electronic thermometers are usually readable to 0.1 °C. Special instruments can give readings to one thousandth of a degree. However, this pr…
Indirect methods of temperature measurement
Thermal expansion Utilizing the property of thermal expansion of various phases of matter. Pairs of solid metals with different expansion coefficients can be used for bi-metal mechanical thermometers. Another design using this principle is Breguet's thermometer. Some liquids possess relatively high expansion coefficients over a useful temperature ranges thus forming the basis for an alcohol or mercury thermometer. Alternative designs using this principle are the rev…