A clinical mercury thermometerGalileo thermometerMercury-in-glass thermometer
Discover great deals on the many hard to find and one of a kind items available only on eBay!

Thermometers

A thermometer is a device that measures temperature or temperature gradient, using a variety of different principles. The word thermometer is derived from two smaller word fragments: thermo from the Greek for heat and meter also from Greek, meaning to measure. more...

HomeHome
Bird & Wildlife AccessoriesBird & Wildlife Accessories
Garden DécorGarden Décor
Flags & FlagpolesFlags & Flagpoles
Garden StakesGarden Stakes
Gazing BallsGazing Balls
OtherOther
Plaques & SignsPlaques & Signs
Rain GaugesRain Gauges
Statues & Yard ArtStatues & Yard Art
Stepping Stones & RocksStepping Stones & Rocks
SundialsSundials
ThermometersThermometers
Water FeaturesWater Features
WeathervanesWeathervanes
Wind ChimesWind Chimes
WindmillsWindmills
Windsocks & DevasWindsocks & Devas
Garden Structures & FencingGarden Structures & Fencing
Gardening & PlantsGardening & Plants

A thermometer has two important elements, the temperature sensor (e.g. the bulb on a mercury thermometer) in which some physical change occurs with temperature, plus some means of converting this physical change into a value (e.g. the scale on a mercury thermometer). Industrial thermometers commonly use electronic means to provide a digital display or input to a computer.

Thermometers can be divided into two groups according to the level of knowledge about the physical basis of the underlying thermodynamic laws and quantities. 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 (see Johnson–Nyquist 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.

Secondary thermometers are most widely used because of their convenience. Also, they are often much more sensitive than primary ones. For secondary thermometers knowledge of the measured property is not sufficient to allow direct calculation of temperature. They have to be calibrated against a primary thermometer at least at one temperature or at a number of fixed temperatures. Such fixed points, for example, triple points and superconducting transitions, occur reproducibly at the same temperature.

Internationally agreed temperature scales are based on fixed points and interpolating thermometers. The most recent official temperature scale is the International Temperature Scale of 1990. It extends from 0.65 K to approximately 1358 K (−272.5 °C to 1085 °C).

Early history

Various authors have credited the invention of the thermometer to Abū Alī ibn Sīnā (usually known as Avicenna), Cornelius Drebbel, Robert Fludd, Galileo Galilei or Santorio Santorio. But the thermometer was not a single invention, it was a development.

Philo and Hero of Alexandria knew of the principle that certain substances, notably air, expand and contract and described a demonstration, in which a closed tube partially filled with air had its end in a container of water. The expansion and contraction of the air caused the position of the water/air interface to move along the tube.

Similar devices used to show the hotness and coldness of the air with a tube in which the water level is controlled by the expansion and contraction of the air, were developed by Avicenna in the early 11th century, and by several European scientists in the 16th and 17th centuries, notably Galileo Galilei. As a result, devices were shown to produce this effect reliably, and the term thermoscope was adopted because it reflected the changes in sensible heat (the concept of temperature was yet to arise). The difference between a thermoscope and a thermometer is that the latter has a scale. Though Galileo is often said to be the inventor of the thermometer, what he produced was a thermoscope.

Read more at Wikipedia.org


[List your site here Free!]

Decorative Salmon Thermometer & Barometer: 24 Inches Long, Made Of Wood Rare!Decorative Salmon Thermometer & Barometer: 24 Inches Long, Made Of Wood Rare! $39.95 Wall Thermometer Aluminum Bronze 11.75 in.Wall Thermometer Aluminum Bronze 11.75 in. $11.95
Oregon Scientific Thgr122Nx Wireless Temperature and Humidity Sensor NewOregon Scientific Thgr122Nx Wireless Temperature and Humidity Sensor New $25.87 Glass Savon de Marseille Indoor/Outdoor Thermometer, NewGlass Savon de Marseille Indoor/Outdoor Thermometer, New $15.24
Springfield 12" Bamboo Poly Resin Clock with Thermometer 91496NSpringfield 12" Bamboo Poly Resin Clock with Thermometer 91496N $29.95 Luster Leaf Evesham 20054 Clock and ThermometerLuster Leaf Evesham 20054 Clock and Thermometer $68.52
Mini Lcd Digital Thermometer Hygrometer Room Temperature Humidity Meter DetectorMini Lcd Digital Thermometer Hygrometer Room Temperature Humidity Meter Detector $2.62 La Crosse Technology 302-604S Silver Indoor Digital Thermometer & Hygrome. NewLa Crosse Technology 302-604S Silver Indoor Digital Thermometer & Hygrome. New $23.24
Springfield Outdoor Thermometer 13-Inch Winter DeerSpringfield Outdoor Thermometer 13-Inch Winter Deer $18.80 Cherry & Gold Finish Desktop Liquid Galileo Thermometer [Id 29691]Cherry & Gold Finish Desktop Liquid Galileo Thermometer [Id 29691] $170.23 List price: Previous Price $285.60
Acurite Wireless Indoor/Outdoor Thermometer with Clock, NewAcurite Wireless Indoor/Outdoor Thermometer with Clock, New $18.54 Springfield Precision Instruments Decorative 14-Inch Patio Thermometer withSpringfield Precision Instruments Decorative 14-Inch Patio Thermometer with $64.64
La Crosse Wireless Thermometer Indoor Outdoor Weather Girl Icon Weather StationLa Crosse Wireless Thermometer Indoor Outdoor Weather Girl Icon Weather Station $24.99 Comfortminder Hygrometer/Thermometer in Brass [Id 1624007]Comfortminder Hygrometer/Thermometer in Brass [Id 1624007] $260.48 List price: Previous Price $432.00
Indoor Outdoor Plastic Jumbo ThermometerIndoor Outdoor Plastic Jumbo Thermometer $8.95 Digital Thermometer Humidity Meter Room Temperature Indoor Lcd HygrometerDigital Thermometer Humidity Meter Room Temperature Indoor Lcd Hygrometer $0.01
Garden Collection Thermometers (Hummingbirds) NewGarden Collection Thermometers (Hummingbirds) New $7.89 Metal Outdoor Clock With Thermometer With Ambient Temperature CheckMetal Outdoor Clock With Thermometer With Ambient Temperature Check $44.99
Welcome Sign Thermometer - Hummingbird Mertal&Glass Sunset Vista 90718Welcome Sign Thermometer - Hummingbird Mertal&Glass Sunset Vista 90718 $19.00 Round Lcd Digital Indoor Thermometer Hygrometer Temperature Humidity Meter GaugeRound Lcd Digital Indoor Thermometer Hygrometer Temperature Humidity Meter Gauge $2.89 to $2.94
204-154C La Crosse 4" Indoor/Outdoor Window Thermometer - More Wine204-154C La Crosse 4" Indoor/Outdoor Window Thermometer - More Wine $5.95 John Deere Resin Handpainted Thermometer Farm Scene Rc 2860John Deere Resin Handpainted Thermometer Farm Scene Rc 2860 $16.96 Was: Previous Price $19.95
Bulova Temp-A-Light 14" Indoor/Outdoor Weather Resistant Thermometer C4827Bulova Temp-A-Light 14" Indoor/Outdoor Weather Resistant Thermometer C4827 $78.30 Windmate 200 Wind Meter with Wind Direction - Wm-200Windmate 200 Wind Meter with Wind Direction - Wm-200 $173.77
Bey-Berk Barometer and ThermometerBey-Berk Barometer and Thermometer $19.99 Wall Thermometer Aluminum Silver 11.75 in.Wall Thermometer Aluminum Silver 11.75 in. $11.95
Taylor Weather Guide Wireless Indoor/Outdoor Thermometer Model 1528Taylor Weather Guide Wireless Indoor/Outdoor Thermometer Model 1528 $16.00 Lilys Home 21 Inch Liquid Galileo Thermometer with Ten Multi-Color Floats and GLilys Home 21 Inch Liquid Galileo Thermometer with Ten Multi-Color Floats and G $57.09
Digital Lcd Indoor Outdoor Thermometer Hygrometer Temperature Humidity MeterDigital Lcd Indoor Outdoor Thermometer Hygrometer Temperature Humidity Meter $2.89 to $3.33 Decorative Thermometer-Purple Floral Pattern On Faux Stone-1997 Udc-Very NiceDecorative Thermometer-Purple Floral Pattern On Faux Stone-1997 Udc-Very Nice $8.49
Rivers Edge Products Due to Price Increase Tin Thermometer, New, Free ShippingRivers Edge Products Due to Price Increase Tin Thermometer, New, Free Shipping $15.29 LaCrosse 104-114 Round Thermometer, 14"LaCrosse 104-114 Round Thermometer, 14" $15.17
AcuRite 02023 Digital Indoor/Outdoor Thermometer with Clock BlackAcuRite 02023 Digital Indoor/Outdoor Thermometer with Clock Black $34.72 mini digital lcd indoor temperature humidity meter thermometer hygrometermini digital lcd indoor temperature humidity meter thermometer hygrometer $9.77
Birds of a Feather Hummingbird Thermometer Metal & Glass Sunset Vista 90718Birds of a Feather Hummingbird Thermometer Metal & Glass Sunset Vista 90718 $15.99 American Expedition Loon Tin Back Porch Thermometer, New, Free ShippingAmerican Expedition Loon Tin Back Porch Thermometer, New, Free Shipping $17.24
AcuRite 02345 8-Inch Rain Gauge & Thermometer Swivel CombinationAcuRite 02345 8-Inch Rain Gauge & Thermometer Swivel Combination $17.66 New! Acu Rite Acurite Indoor Outdoor Digital Thermometer W/ Submer Probe 00890A1New! Acu Rite Acurite Indoor Outdoor Digital Thermometer W/ Submer Probe 00890A1 $14.99
AcuRite 02309 Weathered Copper Tube Thermometer with Sun and Moon Accents NewAcuRite 02309 Weathered Copper Tube Thermometer with Sun and Moon Accents New $23.36 Taylor Precision Products Patio Thermometer (18-Inch)Taylor Precision Products Patio Thermometer (18-Inch) $40.74
Click to see more Thermometers items at www.ebay.com
Prices current as of last update, 09/24/17 3:28pm.

Home Contact Resources Exchange Links eBay