New article posted: Temperature Corrections for Hydrometers

[Randy Holmes-Farley]

A new article of mine on "Temperature Corrections for Hydrometers" has posted at:

http://reefkeeping.com/issues/2004-07/rhf/index.htm

[Boomer]

Wait do yah know. The first true SG table for a 77 F hydrometer. More accurate than my "cheat" form one also :D Wait till some see the words " specific gravity" and "density' used in the same sentence, indicating that they are not the same thing. You would be amazed at how many people think they are one and the same, two interchangeable words :eek2:

Nice job Randy :D

I found this to day while checking on another thread;


Estimation of Specific Gravity Conversion From
One Temperature to Another

If it is assumed that the change in specific gravity with
temperature is approximately 0.001 per 3°C (0.00033/°) for
all processing solutions (see the INTRODUCTION), the
specific gravity can be converted from one temperature to
another by:


specific gravity @ T2/y = (T1 - T2)k + specific gravity @ T1/y

Where

T1 = original temperature, °C
T2 = second temperature, °C
k = change in specific gravity per °C (0.00033)
y = a constant (temperature of the water standard)

Example:

T1 = original temperature, 27.0°C
T2 = second temperature, 25.0°C
k = change in specific gravity per °C (0.00033)


specific gravity @ T2/y = (27.0 - 25.0)(0.00033) + 1.020
specific gravity @ T2/y = 0.00066 + 1.020
specific gravity @ T2/y = 1.021

[Boomer]

And people think I'm picky :rollface:

1.0264 = 35."03"ptt . I couln't figure out why your table was off a couple of 10ths until I saw that 35.03, instead of 35 ppt :D Where did you ge that from, I have Millero at 34.9916 and 35.0009. Never mind, I just found it in Pilson, PSU std 35.03 ;) In-situ density = 1023.3657317337288 kg/m^3

[Randy Holmes-Farley]

1023.3657317337288

You sure it isn't 1023.3657317337287? :lol: