Calibrating swingarm hydrometer?

[herostar]

Ok, so I know you can't really "calibrate" a swingarm hydrometer, but isn't there an easy way to tell if yours is even close? I read HERE (http://reefkeeping.com/issues/2006-12/rhf/index.php) that you can use a solution of 73.1g iodized salt and 2.0 L of pure water to get a mixture that's pretty much 35 ppt (~1.0264 on a hydrometer) to use to calibrate a refractometer. I figure it will work on a swingarm too. What are your comments/ideas on this?

[Rockitmakr]

None come to mind. The swingarm types are all slightly different IMO. If there is a tiny bubble stuck on the swingarm anywhere it will give you a false reading. I use a refractometer & never have any issues. I check it every month so I know it is reliable.
:beer:

[Bojan]

You have to use s.g. calibration standard.

Everthing is in the following article.

http://www.reefkeeping.com/issues/2004-06/rhf/index.php

[Randy Holmes-Farley]

That recipe in the first post is only for refractometers, but a similar one, in Bojan's post, will work for a swing arm, and any other type of hydrometer. :)