OHAUS Pionnier PX85 Manuel D'instruction page 16

EN-14 PX Series Balance
Place the Support into position over the bracket making sure the Support does not make contact with the Bracket
as shown in illustration.
Install beaker on support as shown.
NOTE: Beaker and thermometer are not supplied as part of the density kit.
The density Q is the quotient of the mass m and the volume 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 Discovery 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:
The balance allows direct determination of the buoyancy P (P =A - B) and consequently the above formula can be
simplified:
Q = Density of the solid
A = Weight of the solid in air
B = Weight of the solid in the auxiliary liquid
Q0 = Density of the auxiliary liquid at a given temperature (this value depends on the temperature). The density
table for water is included in Discovery balances.
P = Buoyancy of the solid in the auxiliary liquid (corresponds to A-B).