Hanneman Direct Reading Specific Gravity Balance
For
measuring the specific gravity of gems and minerals, the Hanneman balance
is perfect. It is easy to use and very sensitive and accurate. This revolutionary tool
is the only specific gravity tester that offers direct reading
of the specific gravity value. You needn’t make any calculations - just
read the specific gravity value directly off of the scale. The Hanneman Balance
covers the full range of specific gravity values - from 0 to 22, and you
can measure stones as lightweight as 1 carat (or as heavy as 30 grams).
What
are the components of the balance? This device is basically a modified beam
balance. Its beam suspends from a center pivot point. The right side of the beam
has a fine pointer (see right) that is adjusted to a “zero” position.
Suspended from the left side of the balance is a weighing pan, including an
upper pan for weighing the stone in air and a lower pan for weighing the stone
in water (below left).
Hanging
from the right end of this beam is a counterweight holder to which
counterweights (above right) are added as necessary to move the pointer to zero.
Finally, the right half of the beam incorporates a graduated scale showing
specific gravity values from 0 to 20 (see below right).
How do I use the Hanneman Balance? There are two
simple steps. First, place the stone on the upper weighing pan, then add
counterweights until the beam pointer returns to the zero position. Secondly,
place the stone in the underwater weighing pan, then slide the counterweight
holder, with counterweights, left along the beam until the beam pointer comes to
rest at the zero position.
You’re done - read the specific gravity value to
which the counterweight holder is pointing. You can see in the picture below,
that in this case, the stone’s specific gravity is 3.13.
What’s included
with the balance? Everything needed to measure the specific gravity of your
stones, except water: