Editing Thermometer (section)

== Applications ==
{{See also|List of temperature sensors}}
Thermometers utilize a range of physical effects to measure temperature. Temperature sensors are used in a wide variety of scientific and engineering applications, especially measurement systems. Temperature systems are primarily either electrical or mechanical, occasionally inseparable from the system which they control (as in the case of a mercury-in-glass thermometer). Thermometers are used in roadways in cold weather climates to help determine if icing conditions exist. Indoors, [[thermistor]]s are used in climate control systems such as [[air conditioner]]s, freezers, [[heater]]s, [[refrigerator]]s, and [[Water heating|water heater]]s.<ref name="thermouse"/> Galileo thermometers are used to measure indoor air temperature, due to their limited measurement range.

Such [[liquid crystal thermometer]]s (which use [[thermochromic]] liquid crystals) are also used in [[mood ring]]s and used to measure the temperature of water in fish tanks.

[[Fiber Bragg grating]] temperature sensors are used in [[nuclear power]] facilities to monitor reactor core temperatures and avoid the possibility of [[nuclear meltdown]]s.<ref>{{Cite journal | last1 = Fernandez | first1 = Alberto Fernandez | author-link1 = Alberto Fernandez Fernandez| last2 = Gusarov | first2 = Andrei I.| last3 = Brichard | first3 = Benoît| last4 = Bodart | first4 = Serge| last5 = Lammens | first5 = Koen| last6 = Berghmans | first6 = Francis| last7 = Decréton | first7 = Marc| last8 = Mégret | first8 = Patrice| last9 = Blondel | first9 = Michel| last10 = Delchambre | first10 = Alain| doi = 10.1117/1.1475739 | title = Temperature monitoring of nuclear reactor cores with multiplexed fiber Bragg grating sensors | journal = [[Optical Engineering (journal)|Optical Engineering]]| volume = 41 | issue = 6 | pages = 1246–1254| year = 2002 | citeseerx=10.1.1.59.1761| bibcode = 2002OptEn..41.1246F}}</ref>

=== Nanothermometry ===
[[Nanothermometry]] is an emergent research field dealing with the knowledge of temperature in the sub-micrometric scale. Conventional thermometers cannot measure the temperature of an object which is smaller than a [[micrometre]], and new methods and materials have to be used. Nanothermometry is used in such cases. Nanothermometers are classified as [[luminescent]] thermometers (if they use light to measure temperature) and [[mwod:nonluminous#:~:text=: not emitting light : not luminous, substantial amount of nonluminous matter.—|non-luminescent]] thermometers (systems where thermometric properties are not directly related to luminescence).<ref>{{Cite journal |doi = 10.1039/C2NR30663H|pmid = 22763389|title = Thermometry at the nanoscale|journal = Nanoscale|volume = 4|issue = 16|pages = 4799–829|year = 2012|last1 = Brites|first1 = Carlos D. S.|last2 = Lima|first2 = Patricia P.|last3 = Silva|first3 = Nuno J. O.|last4 = Millán|first4 = Angel|last5 = Amaral|first5 = Vitor S.|last6 = Palacio|first6 = Fernando|last7 = Carlos|first7 = Luís D.|bibcode = 2012Nanos...4.4799B|hdl = 10261/76059|hdl-access = free}}</ref>

=== Cryometer ===
{{main|cryometer}}
Thermometers used specifically for low temperatures.

=== Medical ===
{{main|Medical thermometer}}
[[File:Kinsa QuickCare Thermometer.jpg|thumb|A Kinsa QuickCare [[smart thermometer]].]]

*[[Medical thermometer#Ear|Ear thermometers]] tend to be an [[infrared thermometer]].
*[[Medical thermometer#Forehead|Forehead thermometer]] is an example of a [[liquid crystal thermometer]].
*[[rectal thermometer|Rectal]] and [[Medical thermometer#Oral|oral]] thermometers have typically been mercury but have since largely been superseded by [[NTC thermistor]]s with a digital readout.<ref>{{cite patent |country=US |number=6854882 |status=Active |title=Rapid response electronic clinical thermometer  |pubdate=2005-02-15 |gdate= |fdate=2002-12-04 |pridate= |inventor=Ming-Yun Chen |invent1= |invent2= |assign1=Actherm Inc. |assign2= |class= |url=https://patents.google.com/patent/US6854882B2}}</ref>

Various thermometric techniques have been used throughout history such as the [[Galileo thermometer]] to thermal imaging.<ref name=Ring2007/>
[[Medical thermometer]]s such as mercury-in-glass thermometers, infrared thermometers, [[pill thermometer]]s, and [[liquid crystal thermometer]]s are used in [[health care]] settings to determine if individuals have a [[fever]] or are [[hypothermia|hypothermic]].

=== Food and food safety ===
Thermometers are important in [[food safety]], where food at temperatures within {{Convert|41|and|135|F|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.<ref name="thermouse">{{cite web |url=http://www.foodsafetysite.com/resources/pdfs/EnglishServSafe/ENGSection5.pdf |title=Food Safety: Thermometers |author=Angela M. Fraser, Ph.D. |publisher=[[North Carolina State University]] |date=2006-04-24 |access-date=2010-02-26 |pages=1–2}}</ref>
Cooking thermometers are important for determining if a food is properly cooked. In particular [[meat thermometer]]s are used to aid in cooking meat to a safe internal temperature while preventing over cooking. They are commonly found using either a [[Bimetallic strip|bimetallic]] coil, or a thermocouple or thermistor with a digital readout.
[[Candy thermometer]]s are used to aid in achieving a specific water content in a sugar solution based on its boiling temperature.

=== Environmental ===
*[[Indoor-outdoor thermometer]]
*[[Heat meter]] uses a thermometer to measure [[rate of heat flow]].
*[[Thermostats]] have used bimetallic strips but digital thermistors have since become popular.
[[Alcohol thermometer]]s, [[infrared thermometer]]s, mercury-in-glass thermometers, [[recording thermometer]]s, [[thermistor]]s, and [[Six's thermometer]]s (maximum-minimum thermometer) are used in [[meteorology]] and [[climatology]] in various levels of the [[atmosphere]] and oceans. [[Aircraft]] use thermometers and [[hygrometer]]s to determine if [[atmospheric icing]] conditions exist along their [[Airway (aviation)|flight path]]. These measurements are used to initialize [[Weather forecasting|weather forecast models]]. Thermometers are used in roadways in cold weather climates to help determine if icing conditions exist and indoors in climate control systems.