Thermometers for Oven, Child, Cryostat, Sun: Accuracy & Usage

[bon]

Homework Statement

Describe the thermometer you would use for measuing the temperature of each of the objects listed below, indicating the thermometers approximate accuracy:

a) a domestic oven
b) a sick child
c) a cryostat at about 4K
d) the sun

Homework Equations

The Attempt at a Solution

No idea really!

I\'m guessing the one for a sick child would be your ordinary mercury thermometer that work by a change in volume in the liquid? its approximate accuracy is like +/- 0.5K right? What about the others?!
THanks

 

[jambaugh]

Well you can eliminate the ordinary mercury thermometer for measuring the sun's temperature since it will vaporize long before giving an accurate reading... so presuming you figured that one out already you have some idea. Try thinking out loud here.

 

[bon]

Ok so I guess the sun one is done by spectral lines or something? What about the others? Cant really think out loud as I just don't know what different types there are.. :(

 

[Jobrag]

http://en.wikipedia.org/wiki/Temperature_measurement
Would be a good place to start

 

[rwisz]

for your question! I would approach this problem by first understanding the temperature range and conditions of each object.

a) For a domestic oven, I would use a thermometer with a temperature range of 0-500 degrees Fahrenheit and an accuracy of +/- 1-2 degrees Fahrenheit. This would allow me to accurately measure the temperature inside the oven while cooking.

b) For a sick child, I would use a digital thermometer with a temperature range of 90-110 degrees Fahrenheit and an accuracy of +/- 0.1 degrees Fahrenheit. This would allow me to quickly and accurately measure the child's body temperature and monitor any changes.

c) For a cryostat at 4K, I would use a specialized thermometer such as a platinum resistance thermometer or a thermocouple with a temperature range of -200 to 500 degrees Celsius and an accuracy of +/- 0.1 degrees Celsius. These thermometers are specifically designed for low temperature measurements and can provide precise readings in extreme conditions.

d) For the sun, I would use a pyrometer, which measures temperature by detecting thermal radiation. The accuracy of a pyrometer can vary depending on the type and model, but a high-quality pyrometer can have an accuracy of +/- 1 degree Celsius. However, it's important to note that measuring the temperature of the sun can be challenging and requires advanced techniques and equipment.

Overall, it's important to choose a thermometer with an appropriate temperature range and accuracy for the specific object being measured. Using the wrong thermometer can result in inaccurate readings and potentially compromise the results of an experiment or measurement.