All Questions

0
votes
1answer
69 views

Measure temperature of a heater wire

I would like to measure the temperature of a heating wire (tungsten) that's wrapped around my sample. Does anyone have a better idea than using a infrared thermometer, which has relatively low ...
23
votes
3answers
4k views

How is temperature defined, and measured?

In questions like this one, temperatures of millions of degrees (Celsius, Kelvin, it doesn't really matter at that point) are mentioned. But, what does it mean exactly? What is measured, and how? As ...
1
vote
1answer
65 views

Uncertainty in the temperature measurement using an oscillator coupled to a bath

I'm considering a harmonic oscillator coupled to a bath (e.g. a gas). The oscillator is subject to a damping and a fluctuating Langevin force $$ m\ddot{x} + m\gamma\dot{x} + kx =F_\mathrm{fluct}, $$ ...
6
votes
1answer
530 views

How do we actually measure the temperature of a BEC?

I guess quite some people here are familiar with Bose-Einstein condensates (BEC) and their properties. We know that the necessary temperature for condensation is given by $$ T_C \simeq 3.3125 \frac{\...
4
votes
3answers
412 views

Definition of temperature: “absolute” temperature and linear relations between temperature and thermometric properties

I'm confused about the definition of temperature, and I would like to make some points clearer since I did not find an explanation. Firstly I have heard of three adjectives regarding temperature (...
2
votes
1answer
125 views

Are there any industry usage for gas thermometer? [closed]

I've been searching on this for a while now. Are there any specific advantages and disadvantages for using gas thermometer? Are there any specific industry usage for this kind of thermometer?
1
vote
0answers
982 views

Estimate heating wires temperature

Im design a power supply to work with heating wires and one of the task is to estimate the temperature of the bare wire for a given current or power consumption. I've tried to measure the temperature ...
3
votes
0answers
245 views

How are the melting points of metals measured

How are melting points of metals measured? What are the apparatuses used and how do they "conceive" heat units?
0
votes
1answer
2k views

How do we measure thermal energy?

My textbook says "The amount of thermal energy is found by measuring the temperature of the substance." However, how is this true? Temperature measures only the average kinetic energy of the particles ...
0
votes
0answers
37 views

What is source of Infrared Radiation from some solid object? [duplicate]

I use a Fluke infrared temperature measurement meter for various applications. I have not thought too much about the source of that infrared radiation until recently. Assume some solid with maybe a ...
4
votes
2answers
272 views

How to measure temperature of a laser cooled sample at picoKelvin temperatures?

I'm reading about laser cooling.. my question is: how can the temperature of the sample be measured? (using laser cooling we can reach $10^{-12}K...)$
4
votes
2answers
594 views

Does measuring the air temperature near a 21 lane asphalt highway impact measurements?

The official temperature in Sydney is measured at the Sydney Observatory. This is located near the city side of the Sydney Harbour Bridge - which is a major highway. My question is Does measuring ...
1
vote
4answers
3k views

Can a thermometer really measure the temperature of a substance?

When we measure the temperature of a substance by using a thermometer and waiting until the two come into thermal equilibrium, the thermometer will not display the original temperature of the ...
9
votes
4answers
2k views

Doesn't the use of a thermometer alter the temperature of the system?

If I place a mercury thermometer in hot water, heat energy will transfer from the water to the mercury inside the thermometer. Will this continue until thermal equilibrium is reached and thus the ...
4
votes
2answers
2k views

Measuring Cryogenic Temperatures

I need an inexpensive instrument to measure cryogenic temperatures (down to -200C). I can build a thermistor-based thermometer using an Arduino that is accurate to under 1 degree for 0 to 100C. ...
5
votes
2answers
152 views

Is there a naturally occuring sound pressure level reference?

There are lots of devices that purport to measure the absolute value of sound pressure levels. Here is an example, here's another, there's also this iPhone App. Putting such devices side-by-side in ...
11
votes
4answers
6k views

Why does an infrared thermometer display very low temperature when being directed to the outer air?

I'm toying with an infrared thermometer - one which you point onto an object, press the button and it instantly measures the temperature by estimating the infrared radiation from the object. It shows ...
5
votes
1answer
711 views

How do I measure the temperature of a tiny water droplet?

How do I accurately (+/- 0.1 degrees Celsius or better) measure the temperature of a small (5 to 50 microliter) water droplet without noticeably affecting its temperature? The mass of a thermistor or ...
6
votes
3answers
2k views

How Is It Possible To Measure Extreme Temperatures? (>2 Billion Kelvin)

Linked Article: Record Set for Hottest Temperature on Earth: 3.6 Billion Degrees in Lab Scientists have produced superheated gas exceeding temperatures of 2 billion degrees Kelvin, or 3.6 billion ...