Specific Gravity Resource
Specific Gravity (SG) is the ratio of the object’s density to that of water. Since water has a specific gravity of 1 at sea level, liquids and substances with a specific gravity lower than 1 will float in water. Therefore it is important to select the proper float switch and float for your application. When using oils, Buna or NBR floats are best. These floats have low specific gravity, around .5, and will float well in most petroleum products ranging from .7 to .86 SG. For example, a float switch with a specific gravity of .8 will float well in water but will sink in alcohol which is around .72 SG.
Below is a table liquid for reference.
| Liquid | SG @ 60°F / 15.6°C |
|---|---|
| Tap Water (Reference) | 1.0 |
| Automotive Oil | 0.88 – 0.94 |
| Beer | 1.01 |
| Carbon Tetrachloride CCl4 | 1.59 |
| Corn Oil | 0.924 |
| Crude Oil | 0.79 – 0.86 |
| Diesel Fuel Oils 20 | 0.82 – 0.95 |
| Ethylene Glycol | 1.125 |
| Gasoline | 0.68 – 0.74 |
| Kerosene | 0.78 – 0.82 |
| Jet Fuel (av) | 0.62 |
| Lard Oil | 0.91 – 0.93 |
| Liquid | SG @ 60°F / 15.6°C |
|---|---|
| Machine Lubricants | 0.88 – 0.94 |
| Milk | 1.02 – 1.05 |
| Peanut Oil | 0.92 |
| Propylene Glycol | 1.038 |
| Sodium Chloride 5% | 1.037 |
| Sodium Hydroxide (caustic soda) | 1.22 |
| Sulphuric Acid 95% | 1.839 |
| Sulphuric Acid 20% | 1.14 |
| Triethylene Glycol | 1.125 |
| Turpentine | 0.86 – 0.87 |
| Water, Fresh | 1.0 |
| Water, Sea | 1.03 |
For more information on SG, please visit the following:
Specific Gravity Liquids