Name: kelvin temperature and gas thermometer standards
Uploaded: 2023-04-30T12:29:16.000Z
Duration: 1 min 22 s
Channel: JoVE

K12 Standards

Texas Essential Knowledge and Skills

High School

Chemistry

CHEM.13

CHEM.13.D

Gas Thermometers and the Kelvin Scale

Bir gaz termometresi, doldurulan gazın basıncındaki veya hacmindeki değişikliklere bağlı olarak sıcaklığı değerlendirir.
İki tür gaz termometresi vardır: sabit hacimli ve sabit basınçlı ve sabit hacimli gaz termometresi en yaygın kullanılanıdır.
Bu termometrenin prensibi, sabit hacimde, sıcaklık arttıkça bir gazın basıncının artmasıdır.
Gaz termometresini kalibre etmek için 0 ve 100 santigrat derecedeki basınç ölçülür.
Bu değerler, sıfır basınç sıcaklığını bulmak için tahmin edilen düz bir çizgide çizilir.
Bu sıcaklık Kelvin ölçeğinin sıfır noktasıdır. SI sıcaklık birimi Kelvin olduğundan, bu standart sıcaklık ölçeğidir.
Mutlak sıfır, termal enerjinin mutlak yokluğunu ideal olarak yansıtan mümkün olan en düşük sıcaklıktır.
Kelvin ölçeğinde suyun donma noktası 273.15, kaynama noktası ise 373.15'tir. Aradaki fark, Celsius ölçeğindekiyle aynıdır; Sadece sıfır noktası farklıdır.
Böylece Kelvin ve Celsius ölçekleri arasındaki ilişki kolayca kurulabilir.

<ol>
	<li>Stax'ı açın. (2019). Üniversite Fiziği Cilt 2. [Web sürümü]. <a href="https://openstax.org/books/university-physics-volume-2/pages/1-2-thermometers-and-temperature-scales" adresinden alındı>https://openstax.org/books/university-physics-volume-2/pages/1-2-thermometers-and-temperature-scales</a></li>
</ol>

gaz termometreleri ve kelvin Ölçeği

Moleküler hareket açısından sıcaklığın tanımı, moleküllerin ortalama kinetik enerjisinin sıfır (veya kuantum mekaniği tarafından izin verilen minimum) olduğu bir en düşük sıcaklık olması gerektiğini önermektedir. Deneyler, bu tür bir sıcaklık olan mutlak sıfırın varlığını doğrulamaktadır. Mutlak bir sıcaklık ölçeği, sıfır noktasının mutlak sıfır olduğu ölçektir. Bu tür ölçekler, bir ideal gazın hacmi gibi birkaç fiziksel büyüklüğün mutlak sıcaklıkla doğrudan ilişkili olmasından dolayı bilimde kullanışlıdır.

Kelvin ölçeği, bilimde yaygın olarak kullanılan mutlak sıcaklık ölçeğidir.

Kelvin ölçeği, birimlerin SI sisteminin bir parçası olduğu için gerçek tanımı yukarıda verilen tanımdan daha karmaşıktır. İlk olarak, suyun donma ve kaynama noktaları yerine üçlü noktada tanımlanmıştır. Üçlü nokta, buz, sıvı su ve su buharının kararlı bir şekilde bir arada bulunabileceği sıcaklık ve basınç kombinasyonudur. Üçlü nokta sıcaklığı 273.16 K olarak tanımlanmıştır. Bu tanımın avantajı, suyun donma sıcaklığı ve kaynama sıcaklığının basınca bağlı olmasına rağmen, yalnızca bir tane üçlü nokta sıcaklığının olmasıdır.

Ölçeğin belirli noktalarına rağmen, farklı termometreler diğer sıcaklıklar için biraz farklı sonuçlar verir. Bu nedenle, standart bir termometre gereklidir. Metrologlar, bunun için sabit hacimli gaz termometresini seçmişlerdir. Gazla dolu sabit hacimli bir kabın sıcaklık değişikliklerine maruz kalması ve ölçülen sıcaklığın basınç değişimine orantılı olmasıdır. Sonuçlar biraz gazın seçimine bağlı olur, ancak ampuldeki gaz ne kadar seyrekse, farklı gazlar için sonuçlar o kadar iyi uyuşur. Sonuçlar sıfır yoğunluğa ekstrapole edildiğinde, sonuçlar oldukça iyi uyuşur ve sıfır basınç mutlak sıfır sıcaklığına karşılık gelir. Sabit hacimli gaz termometreleri büyük ve yavaş dengeye gelir, bu yüzden çoğunlukla diğer termometreleri kalibre etmek için standart olarak kullanılır.

Gaz Termometreleri ve Kelvin Ölçeği

Sıcaklığın moleküler hareket açısından tanımı, ortalama kinetik enerjinin olduğu mümkün olan en düşük sıcaklığın olması gerektiğini gösterir ...

Education

JoVE Core

Physics

Fizik

Unit 1

Ünite 1

Temperature and Heat

Sıcaklık ve Isı

KEY TERMS AND CONCEPTS

TEMEL TERİMLER VE KAVRAMLAR

kelvin temperature and gas thermometer standards

Kelvin temperature is the absolute scale used in science, and it starts at absolute zero. That zero point matches the lowest possible temperature, where molecular motion reaches zero or the minimum allowed by quantum mechanics. Scientists use this scale because some physical quantities, such as the volume of an ideal gas, depend directly on absolute temperature.

The Kelvin scale is part of the SI system of units, so its definition is more precise than simply using water’s freezing and boiling points. Instead, it is tied to the triple point of water. The triple point is the only temperature and pressure combination where ice, liquid water, and water vapor can all coexist. Its temperature is defined as 273.16 K, which is useful because it does not change with pressure the way water’s freezing and boiling points do.

Even with fixed reference points, different thermometers can give slightly different readings for other temperatures. For that reason, scientists need a standard thermometer. Metrologists use the constant-volume gas thermometer for this job. In this device, a gas in a sealed vessel stays at the same volume while temperature changes, and the temperature is found from the change in pressure.

The choice of gas can affect the results a little. However, the less dense the gas in the bulb, the better different gases agree. When the results are extrapolated to zero density, they match well, and zero pressure corresponds to absolute zero. Constant-volume gas thermometers are large and slow to reach equilibrium, so they are mainly used as standards to calibrate other thermometers.

Kelvin Temperature and Gas Thermometer Standards

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key terms and concepts

Learn how the Kelvin scale is tied to absolute zero, the triple point of water, and constant-volume gas thermometers used to calibrate other thermometers.

Kelvin Temperature and Gas Thermometer Standards | JoVE K12

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Kelvin Temperature and Gas Thermometer Standards

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