Sartorius ME215 Operating Instructions Manual page 79

Equations Used to Determine Density
Buoyancy: Rho = (Wa · (Rhofl – LA)) / ((Wa – Wfl) · Corr) + LA
For the buoyancy method, a factor of 0.99983 (factory setting) is used to
allow for the buoyancy caused by the bars of the sample holder of the YDK
01 (LP) Density Determination Kit. This factor is yielded by allowing for this
equation:
buoyancy of bars/wires = 2 · d
The equation considers the following variables: the number of bars or wires,
the bar/wire diameter of the sample holder, and the inner diameter of the
vessel used.
The correction factor 0.99983 is yielded by 1 – 2 · d
where: 2 = number of wires/bars
d = bar diameter (0.7 mm) for YDK01
D = inner diameter of the vessel (76 mm) for YDK01
If you are using different vessels or other density kits, press
Param.
the
factor.
To determine the density of a solid according to the buoyancy method with
our YDK 01 (LP) Density Determination Kit, make sure to use the beaker with
a 76 mm diameter.
Displacement: Rho = (Wa · (Rhofl – LA)) / (Wfl · Corr) + LA
For the displacement method, a factor of 1.00000 (factory setting) is used to
allow for the buoyancy caused by a wire suspended in the liquid.
If you are using different vessels or other density kits, press
the Param.
factor.
The equation considers the following variables: the number of wires or bars,
the wire/bar diameter of the sample holder, and the inner diameter of the
vessel used.
This factor is yielded by: Corr = 1 – χ · d
χ = number of wires
where:
d = wire diameter
D = inner diameter of the vessel
Rhofl = density of the liquid causing buoyancy
Wa = weight of sample in air
Wfl = weight of the sample in liquid/buoyancy of sample
Corr = correction for buoyancy produced by the immersed
wires or bars of the sample holder:
– = 0.99983 for the buoyancy method
– = 1 for the displacement method
LA = correction for air buoyancy = 0.0012 g/ccm
Pycnometer: Rho = (Wa · (Rhofl – LA)) / (Wfl + Wa – Wr) + LA
where: Rhofl = density of the reference liquid
Wa = weight of the sample
Wfl = weight of the reference liquid
Wr = weight of sample + the reference liquid
LA = correction for air buoyancy = 0.0012 g/ccm
2 2
/ D (Wa – Wfl)
soft key to enter any necessary changes to this calculation
soft key to enter any necessary changes in this calculation
2 2
/ D
2 2
/ D
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