Answer a question and then ask a question
- Thread starter killafins
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thomas712
Guest
Originally posted by dburr
Q. whats the differance between SG and salanity?
A. The easiest and most common instrument to measure the salt concentration in aquaria is the hydrometer. A hydrometer is a device that measures the density or specific gravity of a liquid. The more salt in the water the more dense it is.
It is important to understand that salinity and specific gravity are related - but not the same. Salinity can be measured by (a) boiling down a water sample, (b) measuring conductivity by electronic means, and (c) other laboratory methods which are either too complex or too expensive.
Specific gravity indicates density, while salinity refers to the actual weight of the salt.
The hydrometer works on the principle that a solid body displaces its own weight of the liquid in which it floats. The hydrometer is calibrated at 60F (15.55C) in which distilled water equals 1.000 as the initial point. The readings will rise with increasing density of the water.
As the instrument is calibrated at a temperature of 60F (15.55C), it requires that the water to be tested will also have a temperature of 60F (15.55C) in order to get an accurate reading.
Water will expand or contract if temperatures vary; therefore the density fluctuates with temperature as well.
Q. What does ion antagonizim mean?
karajay
Active Member
That's interesting....someone posted a while ago that hydrometers are calibrated at 78*
Also, does this mean that if I measure 80* water with a glass hydrometer that is calibrated at 60*, would the actual sg be higher or lower? Or would the difference be too small to notice?
Also, does this mean that if I measure 80* water with a glass hydrometer that is calibrated at 60*, would the actual sg be higher or lower? Or would the difference be too small to notice?
