Difference between revisions of "Thermometry pchem lec"

From MC Chem Wiki
Jump to navigation Jump to search
(Created page with "Thermometry: measuring temperature. '''Q1: What is temperature? Just a number?''' :A1 - the degree or intensity of heat present in a substance. :A2 - a measurement of the ave...")
 
 
(4 intermediate revisions by the same user not shown)
Line 1: Line 1:
 
Thermometry: measuring temperature.
 
Thermometry: measuring temperature.
  
'''Q1: What is temperature? Just a number?'''
+
===Q1: What is temperature? Just a number?===
 
:A1 - the degree or intensity of heat present in a substance.
 
:A1 - the degree or intensity of heat present in a substance.
 
:A2 - a measurement of the average kinetic energy of a particle in a system; 3/2kT <--per molecule
 
:A2 - a measurement of the average kinetic energy of a particle in a system; 3/2kT <--per molecule
  
'''Q2: How do we measure temperature?'''
+
===Q2: How do we measure temperature?===
:A1 - Most commonly we use a thermometer.
+
:A1 - Most commonly we use a [[Media:The Thermometer.pdf|thermometer]].
 +
[[File:temperature_scale.jpg|400px]]
 +
 
 +
===Temperature is never measured!===
 +
:We measure other system variable and then relate this back to temperature/average kinetic energy of the particles.
 +
::- Most common is change in volume as a function of changes in temperature
 +
::- changes is voltage as a function of changed in temperature ([https://en.wikipedia.org/wiki/Thermocouple thermocouple], used for measuring very hot environments, like kilns or flames.
 +
::- changes is color as a function of changed in temperature  ([https://en.wikipedia.org/wiki/Thermochromism thermochromic])
 +
::- changes is pressure as a function of changed in temperature (used to develop the idea of an absolute zero, zero pressure zero temperature.)
 +
::- IR light emission (intensity/wavelength) as a function of temperature, [https://en.wikipedia.org/wiki/Infrared_thermometer IR thermometer].

Latest revision as of 13:09, 28 August 2020

Thermometry: measuring temperature.

Q1: What is temperature? Just a number?

A1 - the degree or intensity of heat present in a substance.
A2 - a measurement of the average kinetic energy of a particle in a system; 3/2kT <--per molecule

Q2: How do we measure temperature?

A1 - Most commonly we use a thermometer.

Temperature scale.jpg

Temperature is never measured!

We measure other system variable and then relate this back to temperature/average kinetic energy of the particles.
- Most common is change in volume as a function of changes in temperature
- changes is voltage as a function of changed in temperature (thermocouple, used for measuring very hot environments, like kilns or flames.
- changes is color as a function of changed in temperature (thermochromic)
- changes is pressure as a function of changed in temperature (used to develop the idea of an absolute zero, zero pressure zero temperature.)
- IR light emission (intensity/wavelength) as a function of temperature, IR thermometer.