Nova-Tech Density Kit for Adam PW and PGW Series - Manual (Page 10)

APPENDIX A
A method to determine the volume of the float
To determine the volume of the float the following equation can be used.
V
© Adam Equipment Company 2007 8
A - mass of float in air
[g]
B - mass of float in distilled water [g]
V - float volume [cm
3
]
ρ – density of distilled water [g/cm 3 ]
d
– density of air
The following formula is used to determine the density of air
(d) to use in the above equation.
0,0012932 p
d = x
A - B
= [cm 3 ]
ρ - d
1+ 0,0036728 x t 1013,25
Where,
0,0012932 is the density of air [g/cm³] at 0°C and standard
air pressure (1013,25 in Millibars)
0,0036728 is the “Temperature Co-efficient” (the amount by
which the air expands in volume at a constant pressure as
the temperatuire changes)
t
- temperature of air [ o C]
p
- pressure of air in Millibars [mb]
The procedure would be to measure the mass of the float in air (value A)
and the mass while it is submerged in distilled water (value B) and then
put the values in for the water density (ρ) and air density (d) at the
temperature and pressure measured using other instruments.
The values for water density at various temperatures can be found in
most chemistry or physics reference texts. A partial list is given in the
following Appendix.