Thermometer Help: Avoiding Wrong Measurement

[mobb]

ok well my science teacher told us to make a thermometer, i have everything needed for it but i just got one question, all the bottles that we drink on have you know the little mountains those little balls at the bottom, and if it has that then the measurement will be wrong, what can i put inside it to avoid the measurement to be wrong?

 

[Moonbear]

Huh? What do you mean the drink bottles have mountains and balls? What sort of bottles do you have? And why would the shape of a bottle affect the measurement of temperature? I assume you're planning to measure the temperature of some liquid placed inside the bottle?

It would be helpful if you described how you're making your thermometer and what you plan to measure with it (liquid temperature, air temperature, etc), so we can better understand your question.

 

[BobG]

Why would the uneven shape at the bottom make your measurements wrong?

The simplest way to do this is just to put some kind of liquid in the bottle (preferably a liquid that doesn't freeze in winter temperatures such as methyl alcohol). Use a commercially made thermometer to calibrate your homemade thermometer.

If you need to create your temperature scale ahead of time, based on the expected expansion of whatever's in the bottle, the irregular surface on the bottom still isn't a problem. You can fill the bottle and empty it into a beaker or measuring cup to find the volume. Measure the liquid you intend to put in the bottle in a beaker or measuring cup before you put it into the bottle. (Or just fill the bottle completely, since you've already measured the volume).

What materials are you using? There's a cheap version of this experiment, which it sounds like you're using. There's also a more sophisticated version using a test tube, stopper, and glass tubing.

 

[mobb]

this is what I am using

Tap water
Rubbing alcohol
Clear, narrow-necked plastic bottle (11 ounce water bottles work well)
Food coloring
Clear plastic drinking straw
Modeling clay

and this is what i mean by the little mountains

http://img482.imageshack.us/img482/7195/15552ru.jpg

i was thinking of putting sand into it and putting water so it sinks then do the procedure?

 

[mobb]

bump, i really need help on this

 

[FredGarvin]

The liquid will expand and contract with temperature. The shape of the bottle doesn't matter. What does matter is how you make the graduations to show the various temperatures. Reread Bob's post.