Hydrometers are FUBAR.....

[CDaubs]

Very good. Thank you :)

 

[Rcpilot]

:oops:

 

[dcantucson]

The solution is best, but you can also use Distilled Water to calibrate them.

Rc you really should get a refractometer! :lol: Old coot! :mrgreen: :lol:

 

[bjohanson1234]

In RC's defense, They do have electronic salinity meters!
Pinpoint Salinity Monitor

And that is what he is probably thinking of.

As for the float one that he uses, that is the one I was using. It gave me a reading of 1.025 but my refractometer read 1.020 after calibrating.

Brian

 

[Rcpilot]

I like simple measuring devices that I don't have to calibrate.

I don't see any way a floating hydrometer can go out of calibration. Glass doesn't change density. The steel balls that act as a counterweight don't change density. I clean it every time I use it. How can it loose accuracy?

 

[bjohanson1234]

All Im saying is that the one I have might not be calibrated corectly from the factory. Who knows if that little slip of paper didnt move down the neck a bit during shipping? Atleast with a refractometer, I can get it back to where it should be

 

[tankedchemist]

Cause, they do, in fact, change in density. The change is primarily dependent on temperature changes. However, I know that in commercial labs I've worked in, the floating hydrometers I used routinely were calibrated every month.

Here's a nifty way to calibrate it (though not practical for us)... mostly I'm showing this literature to demonstrate that it is standard practice to calibrate floating hydrometers:

http://www.iop.org/EJ/article/0957-...quest-id=54d5ff15-c699-42c0-9dcf-1bc5ef52d7c4

And, a simpler how-to:

How to Calibrate a Hydrometer | eHow.com

 

[Solarfall]

Is there any reason you would use distilled water rather than RO?

Just wondering because people always say distilled in terms of calibrating refractors.

 

[tankedchemist]

That's cause they're lazy. :D the terms are almost interchangable in most labs, actually. The majority of chemists don't distinguish between the two... unless they're cool biochemists. :mrgreen:

 

[bjohanson1234]

:bowdown: Thank you tanked.

Pure water is pure water in my book