How to check you hydrometer and thermometer.

[casebrew]

Lurking here, I've seen several folks who question the accuracy of their instruments. They can be tested very simply. These are the standards on which the technology is based.

Check your hydrometer in clear, room temperature water. It ought to read 1.000000.

Check your thermoneters twice. Once in ice water, it will be 32 degrees F. And again in boiling water, it will be 212 F (at sea level.) Or 0 deg C, and 100 c. Those are the standards used to quatify the "Centigrade" scale to begin with.

How can you be a 'brew pot pilot' if you can't trust your instruments?

 

[david_42]

Another useful check for a brewer is based on the boiling point of ethanol. Put a couple oz. of cheap vodka or bad beer in a small metal can. Place this in a large pan of water and heat. Watch the temperature as it gets near 172F (78C). There will be a point when the temperature stops rising for a while, even though the water in the pan continues to heat up. This is because the alcohol is boiling off. Once it is all got the temperature starts rising again.

 

[bikebryan]

Lurking here, I've seen several folks who question the accuracy of their instruments. They can be tested very simply. These are the standards on which the technology is based.

Check your hydrometer in clear, room temperature water. It ought to read 1.000000.

Check your thermoneters twice. Once in ice water, it will be 32 degrees F. And again in boiling water, it will be 212 F (at sea level.) Or 0 deg C, and 100 c. Those are the standards used to quatify the "Centigrade" scale to begin with.

How can you be a 'brew pot pilot' if you can't trust your instruments?

Hydrometers shouldn't read 1.000 with room temperature water. Most hydrometers are calibrated to 60 F, and I've not met many people who keep their home temp that cool!

 

[casebrew]

Hydrometers shouldn't read 1.000 with room temperature water. Most hydrometers are calibrated to 60 F, and I've not met many people who keep their home temp that cool!

Right, I meant tap temp. Nontheless, the difference of 50 to 70 is .0015. I suspect room temperature will be close enough for home brewers. If not, use an accurate thermometer to check the water temp, and a correction table too... Probably more critical would be to use the same instrument throughout each batch.

But then, in the sauna the room temperature is 140....

 

[El Pistolero]

Nontheless, the difference of 50 to 70 is .0015.

According to the the instructions that came with my hydrometer, the difference between 60 and 72 is .002, and the correction at 78 is .003. At room temp your hydrometer in water should read ~ .0975 (assuming room temp is 75).

 

[Dude]

Hydrometers shouldn't read 1.000 with room temperature water. Most hydrometers are calibrated to 60 F, and I've not met many people who keep their home temp that cool!

Typical ground water in my location is around 50° F, so letting it sit at room temp for a few minutes will get it closer to 60 degrees than you'd think. I happen to have a bottle of Aquafina sitting next to me, room temp, and it is reading 59 degrees. My house is 68° on the button right now.

It seems to me you grasp at straws to prove someone wrong, and that is the only time you ever post.

 

[wild]

Check your hydrometer in clear, room temperature water. It ought to read 1.000000.

Your hydrometer can read 1 at 60°F and still be wrong. See this http://www.honeycreek.us/hydrocal.htm about checking/calibrating your hydrometer.

Good luck,
Wild