46
Balance modes
Q = Density of the solid
A
= Weight of the solid in air
B = Weight of the solid in the auxiliary liquid
Q
0
= Density of the auxiliary liquid at a given temperature (this value depends on the temperature). The density table
for water is included in Voyager balances.
P = Buoyancy of the solid in the auxiliary liquid (corresponds to
A -B).
In the event that a different liquid is to be used, provisions are made to enter the density of the desired liquid and enter
its name into a library. The following procedure uses water.
6.9.2Solid density determinations for items more dense than water
The density
Q
is the quotient of the mass
m
and the volume
V
.
Q
= m
V
Density determinations are performed by using
Archimedes principle
.
This principle states that every solid body
immersed in a fluid loses weight by an amount equal to that of the fluid it displaces. The density table for water is
included in the Voyager balance software.
The density of a solid is determined with the aid of a liquid whose
density, Qo,
is known (water is used as an
auxiliary liquid). The solid is weighed in air
(
A
)
and then in the auxiliary liquid (
B
). The density
Q
can be calculated
from the two weighings as follows:
Q =
A
A -B
_
Q
0
The balance allows direct determination of the buoyancy P
(P =A - B
) and consequently the above formula can be
simplified:
Q =
A
P
_
Q
0
From main menu
Enter CHANGE MODE. Select DENSITY, display advances to LIBRARY NAME.
MAIN MENU
CHANGE MODE
Enter
DENSITY SETUP
LIBRARY NAME
Library name
Enter a library name, up to 8 characters and press
Enter
button. Display
advances to DENSITY SETUP with SOLID DENSITY highlighted. If a previous
name was entered and selected, the balance uses the parameters which
were previously set.
DENSITY SETUP
Enter
LIBRARY NAME
D2
SOLID DENSITY
<-SELECTED
LIQUID DENSITY
AUTO SAMPLE
OFF
AUTO PRINT
OFF
RUN
After you select SOLID DENSITY, display advances to AUX LIQ & MODE with
H2O highlighted.
Summary of Contents for Voyager V10640
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