Floating Hydrometer vs. Refractometer

[crabbychris]

First off this is NOT about swingarm hydrometers...they are junk.
from what i have read on the net floating hydrometers have been used in labs for years and have been proven to be accurate as long as you adjust for temperature. Sg should be checked at 77F and the hydrometer should be checked for accuracy in freshwater to read 1.000, if the reading is off adjust accordingly.
refractometers can be accurate or inaccurate depending on the quality of the unit and correct calibratiion.
i have read that cheap refractometers can be just as inaccurate as swingarms. it seems you would have to buy an expensive refractometer to get results as good or better than a floating hydrometer.
if labs and scientists have been using floating type hydrometers how inaccurate can they be?

 

[camfish]

Originally Posted by CRABBYCHRIS
http:///forum/post/2880862
First off this is NOT about swingarm hydrometers...they are junk.
from what i have read on the net floating hydrometers have been used in labs for years and have been proven to be accurate as long as you adjust for temperature. Sg should be checked at 77F and the hydrometer should be checked for accuracy in freshwater to read 1.000, if the reading is off adjust accordingly.
refractometers can be accurate or inaccurate depending on the quality of the unit and correct calibratiion.
i have read that cheap refractometers can be just as inaccurate as swingarms. it seems you would have to buy an expensive refractometer to get results as good or better than a floating hydrometer.
if labs and scientists have been using floating type hydrometers how inaccurate can they be?

I have both a floating hydrometer and a refractometer. Both are equally accurate, however I've tested my water at different temperatures and the floating hydrometer showed different readings for each sample of salt. Not significant, but even so. My refractometer had atc, so it showed the same reading every time. Now the only problem with refractometers is that with such a small amount of water on the glass, it can evaporate and show slightly higher readings but with the hydrometer, it is in the mass of water, so the reading has no evaporation fault. I will always trust my refractometer over the hydrometer because it is easier to read and use. Get a good refractometer with atc, it won't cost much more and it is a lot easier to read imo. A lot of people simply calibrate their hydrometers with someone elses good refractometer. The actual reading itself isn't what is important though, being consistent is what is important. If your refract/hydro meter is off by a few points, that isn't as big a deal as if it shows different readings every time you use it. So it is compeletely up to you, but no matter what you get, make sure to compare it to someone elses and make sure the readings are consistent with it. Also, make sure to clean the glass on both before storing it. Good Luck.

 

[crabbychris]

Well I have a floating hydrometer and I need to treat a tank with hypo. I have read that they are just as accurate as refractometers as long as temperature is adjusted correctly. anybody here done hypo with one?

 

[gmann1139]

Here's my $.02
Refractometers can't break easily. I've broken at least three floaters in my professional life, and I'm about due to break another.

And a broken hydrometer, even a floater, isn't too accurate.

 

[veni vidi vici]

For day to day use a glass hydrometer is perfectly fine,however if i where doing hypo,i would definitely use a refractometer. I own both and use both.
Here are the temp.corrections for a standard Hydrometer calibrated at 77 deg F:

 

[camfish]

For day to day use a glass hydrometer is perfectly fine,however if i where doing hypo,i would definitely use a refractometer. I own both and use both.
Here are the temp.corrections for a standard Hydrometer calibrated at 77 deg F:QUOTE]
My little test wasn't quite as complex as that

thanks for the chart, pretty cool stuff. I didn't even think of how easy they are to break, but that's true, while I've never broken one (because I don't use them any more), I have broken several similarly made thermometers. It sure isn't fun to clean up all the little shards of glass and floaty ball thingys either.
ATP refractometer you can get one of sleaveybayifyouknowImean that will work perfectly fine.

 

[veni vidi vici]

Originally Posted by Veni Vidi Vici
http:///forum/post/2881602
For day to day use a glass hydrometer is perfectly fine,however if i where doing hypo,i would definitely use a refractometer. I own both and use both.
Here are the temp.corrections for a standard Hydrometer calibrated at 77 deg F:QUOTE]
My little test wasn't quite as complex as that

thanks for the chart, pretty cool stuff. I didn't even think of how easy they are to break, but that's true, while I've never broken one (because I don't use them any more), I have broken several similarly made thermometers. It sure isn't fun to clean up all the little shards of glass and floaty ball thingys either.
ATP refractometer you can get one of sleaveybayifyouknowImean that will work perfectly fine.

 

[crabbychris]

vini I like that idea!