Density determination, Below balance weighing, Specific gravity determination – Scientech HC Series User Manual

Page 10

Advertising
background image

Density Determination:

Scientech does not offer a density determination kit nor do you need one to determine density. Density is mass (grams) per unit
volume (cubic centimeters).

In order to determine density of a solid, place a graduated flask with a known volume of water on the pan of the balance, tare the
balance, and then place the solid in the flask of water. Divide the displayed weight in grams by the increased volume of water. The
result is the mass per unit volume of the solid in g/cc.

To determine the density of a liquid, place an empty graduated flask on the balance weighing pan, tare the balance, then pour the
liquid into the graduated flask. Divide the displayed weight in grams by the volume of the liquid. The result is the mass per unit
volume of the liquid in g/cc.


Below Balance Weighing:

Note: Please use care when using below balance weighing. The balance’s suspension can be damaged if the below balance

weighing hanger is subjected to too much force or a sidewards shock.

For applications requiring suspension of weighings below the balance, a hook is provided. To use below balance weighing refer to figure

2 and proceed as follows.

• Gently turn the balance on its side.

• Remove the hole plug

• Mount the balance on a solid pedestal or surface with a hole under the balance to allow access to the hook.

While using the below balance weighing feature all other functions of the balance operate normally. The balance is capable of weighing

both above and below simultaneously provided the capacity of the unit is not exceeded.


The below balance weighing feature is ideal for determining specific gravity. Specific gravity is the ratio of the mass of a body to the
mass of an equal volume of water. Every mineral has its own specific gravity (SG). A list may be found in any Handbook of
Chemistry and Physics. Specific gravity will classify or authenticate a substance. For instance, a diamond’s SG is 3.50-3.53 while
quartz’s is 2.65. The following section discusses how the below balance weighing feature can be used to determine specific gravity.

Specific Gravity Determination:

An optional specific gravity determination program, SHCSG, is available for all High Capacity Series balances. This option must be
purchased and installed when the balance is purchased. The SCHSG program is installed in place of the front panel parts counting
function. High Capacity Series balances can have either the specific gravity determination program of front panel parts counting, but
not both.

Specific Gravity Determination Using the Optional SHCSG Program:

1. Remove all objects from the weighing pan and press the TARE button. 0.0 will be displayed.
2. Suspend the empty basket from the below balance hook then press the TARE button. Flashing dashes will be displayed until

a stable reading is obtained, then 0.0 will be displayed

3. Press the MENU button so dEnS is displayed.
4. Press the TARE button. t. – H2O is displayed.
5. Suspend the empty basket, from the below balance hook, in water, then press the TARE button. Flashing dashes will be

displayed until a stable reading is obtained, then a negative reading will be displayed.

6. Remove the empty basket from the water.
7. Press the MENU button so dEnS is displayed.
8. Press the CAL button so S. – Air is displayed.
9. Load the sample into the empty basket then suspend the basket from the below balance weighing hook. Press the CAL

button. A flashing S. – Air is displayed until a stable reading is obtained. The balance then beeps and S. – H2O is displayed.

10. Suspend the sample and basket in water then press the CAL button. A flashing S. – H2O is displayed until a stable reading is

obtained, then the density of the sample will be displayed.

11. Press the MENU button to return to the normal weighing mode.


The balance will store the tare values until it is turned off. To determine the specific gravity of another sample, start at step 7. To
reset the tare values, start again at the beginning of the procedure.

10

Advertising