With a name like hydrometer you might pause and say: “…a what?” You might have even gone a step further and added “why do I want one of those?”  Simply put, hydrometers test the density of liquids. Specifically, they compare the density of liquids to the density of water (a comparison called the specific gravity of a substance). A substance’s specific gravity is extremely useful. We use it to tell how creamy milk is, how much alcohol is in spirits, how salty the ocean is, and much more! In the following experiments we’ll test the salinity of several solutions.


(Note: This is different from a hygrometer, which measures the humidity of the air!)


Please login or register to read the rest of this content.

Have a question ?

Tell us what you're thinking...

Comments

5 Responses to “Homemade Hydrometer”

  1. No, fish can’t live in distilled water. They need the minerals found in regular water. Never put fish in distilled water.

  2. ericksonnationmom says:

    QUESTION:
    could fish live in distilled water???

  3. Nancy Babicz says:

    Guess we became our own hydrometers when we floated in the Great Salt Lake in Utah on vacation!

  4. Thanks so much – we’ll fix that in a jiffy!

  5. Terri Cleary says:

    Grammar nit-picking: ” A substances specific gravity… ” in intro paragraph should read: “A substance’s specific gravity…”

    The gravity belongs to the substance. Also, “A” indicates singular, while “substances” is plural.