All Questions
Tagged with measurementsthermodynamics
41 questions
1vote
1answer
42views
Relationship between density and temperature - How to know the precise temperature at which a bell inside a Galileo Thermometer will sink?
A Galileo Thermometer consists of bells placed inside a tube that's filled with liquid. As the temperature increases, the fluid density decreases. This leads to a decrease in the buoyant force, and ...
- 129
1vote
0answers
28views
Does the mean of multiple measurements of one sensor reduce the sensor error, in the case of a data-logged K-type thermocouple?
I'm doing an experiment to measure steady-state heat transfer conditions. I have a hot plate connected to a power supply which supplies a constant current (~1.880A in this run). It is very precise, ...
- 1,287
4votes
2answers
141views
Temperature estimation based on very quick measurements
I want to preface by saying I'm not a physicist, I'm a hardware designer at an R&D center trying to wrap my head around temperature measurements, so please forgive me if my questions are stupid or ...
16votes
5answers
2kviews
Calculating temperature when it is lower than your thermometers can read?
We have an old freezer. I believe the thermostat is broken and think it may run all the time. Food in it gets really cold (Ice cream like concrete). I've tried measuring the temp with a freezer ...
- 163
0votes
2answers
642views
Why do we usually measure liquids and gases by volume?
Why do measure liquids and gases in volume rather than by weight? Isn't that comparatively more inaccurate since volume changes with temperature and pressure?
- 49
-1votes
3answers
195views
Temperature is discrete but not countable? [closed]
So I was reading a a question and top comment on math stack exchange that didn't make sense to me. you can measure the temperature of something, but you can't count it. Incidentally, I claim ...
- 1,401
1vote
1answer
54views
I don't understand how Watt measured the volume of a mass of water vapor compared to that same mass in liquid phase
I don't understand how Watt measured the volume of a mass of water vapor compared to that same mass in liquid phase. In this text he describes the process by himself, but I can't understand it. Could ...
- 113
1vote
1answer
2kviews
Dew point and frost point: definition, calculation and the en.wikipedia.org disambiguation
Good day! I found the definition of dew point and frost point somewhat odd on wikipedia. At the first line you see The dew point is the temperature to which air must be cooled to become saturated ...
- 11
3votes
1answer
509views
Temporal and spatial averaging of macroscopic variables
I am reading Callen's Thermodynamics and an introduction to Thermostatics. Initially the author describes the temporal nature of macroscopic measurements as- A macroscopic observation cannot respond ...
- 446
0votes
1answer
82views
Percentage accuracy of a prediction
Although it appears trivial, I am stuck at the following problem: I am searching for a formula to express the (percentage) accuracy of a prediction about temperature. However, most methods I have ...
2votes
2answers
187views
Measuring the heat capacity of a calorimeter
Heat capacity $C$ is by definition the limit $C=\lim_{\Delta t\to 0}\frac{\Delta Q}{\Delta t}$. Here $\Delta Q$ is the amount of energy transferred as heat onto the material, and $\Delta t$ is the ...
- 293
1vote
0answers
89views
Does there exist a quantities which can be absolutely measured in physics?
In this question, I had an argument with some users about how inexact differentials turn exact under constrained paths. So, the discussion began on this point: For a given path, could we call ...
- 8,249
0votes
0answers
225views
How does a Bourdon tube maintain constant volume?
I would like to understand why a Bourdon tube works, the working principle is described on wikipedia as: The Bourdon pressure gauge uses the principle that a flattened tube tends to straighten or ...
- 940
0votes
1answer
133views
Can a mercury thermometer be curve? Is there any reason they cant be curved?
Is it compulsory for a mercury thermometer to be straight?
2votes
0answers
107views
What is the Joule-Thomson measurements uncertainty?
I will be measuring the Joule-Thomson coefficient for noble gases and I am trying to perform the uncertainty budget analysis prior to the measurements. However, I have my doubts here. The JT ...
- 21
