From the HBD Archive
From: roberts%studguppy@LANL.GOV (Doug Roberts @ Los Alamos National Laboratory)
Subject: More on Specific Gravity & Temperature
Date: 1989-09-08 15:15:23 GMT

I haven't had time to go over to our tech library & research this
completely; however, I can supply a little more info.

1.
> >From: Darryl Richman <darryl@ism780c.isc.com>

> >From: ephram@violet.berkeley.edu
> >">and on Doug Roberts (HBD #236)
> >">
> >"> (T x 1.449E-4 - 0.009) + SG(uncorrected) = SG(corrected)
> >"
> >"This formula does not hold true for 60 degrees F. ...

I agree with another poster who stated the belief that this small
difference is outside the limits of the accuracy of measurement of the
hydrometer and the thermometer.

2.
I extracted (yes, that _was_ a pun) some S.G. info from my 47th
Edition of The HandBook of Physics & Chemistry for pure ethanol.
Realizing fully that this _isn't_ wort data, nevertheless the data
shows a linear relationship of S.G. WRT to temperature (again, within the
limits of the accuracy of measurement).

T(C) S.G. From The Table S.G. From the Equation Delta (%)
S.G. = -0.000837 X T + 0.80625 100 X (Actual - Estimated) / Actual
---------------------------------------------------------------------------------------------------
0 0.80625 0.80625 0.0
10 0.79788 0.79788 0.0
20 0.78945 0.78951 - 0.008%
30 0.78097 0.78114 - 0.02%

3.
Again, from the deep, dark recesses of my memories, I believe that
this linear relationship holds for aqueous sugar solutions as well.

--Doug

================================================================
Douglas Roberts |
Los Alamos National Laboratory |When choosing between two evils,
Box 1663, MS F-602 |I always like to try the one
Los Alamos, New Mexico 87545 |I've never tried before.
(505)667-4569 |
dzzr@lanl.gov |
================================================================

Back New Search

The posts that comprise the Homebrew Digest Searchable Archive remain the property of their authors.
This search system is copyright © 2008 Scott Alfter; all rights reserved.