Hydrometer misreading

[jordanhollins]

Hey all. Recently picked up a bunch of 2nd hand equipment that came with 2 glass hydrometers and a thief. This on top of the plastic one I already have from the coppers DIY kit.

So I went to take a reading today ad thought I would if they were all the same, the are not.
One is showing 1.005 one is 1.010 and the other is 1.015. None of them seem to be cracked. Or any issues that I can see.

How do I know which is correct? Is .010 difference an ok variable?

Thanks in advance.

 

[jvp1]

It is possible they're calibrated for different temperatures. The one I have (I think it's the standard calibration) is good for 60F, and requires you to add or subtract a bit if your brew temperature is higher or lower than that.

 

[Shaneoco1981]

Easy way to tell is to put them all in distilled water. Which ever one reads 1.000 at the temp your beer is, is the one I would use.

 

[jordanhollins]

Easy way to tell is to put them all in distilled water. Which ever one reads 1.000 at the temp your beer is, is the one I would use.

That is a very clever idea. Thanks.
Now is distilled water previously boiled water, or like water that has gone through a brita filter?

 

[Yuri_Rage]

That is a very clever idea. Thanks.
Now is distilled water previously boiled water, or like water that has gone through a brita filter?

Neither. It is distilled, making it very pure. It's cheap at the grocery store.

 

[Shaneoco1981]

Yea, a gallon is like a buck.