2. principle of measurement, 2-1. oscillating u-tube cell – Cannon Instrument D155 Density Meter User Manual
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7-2. Principle of measurement
7-2-1. Oscillating U-tube Cell
When a measurement cell filled with liquid or gas is oscillated spontaneously, resultant oscillating cycle
varies with the density of the sample in the measurement cell. The oscillating cycle T is expressed
follows.
T
dVc Mc
K
=
+
2π
where,
d = Density of sample in measurement cell
Vc = Volume of sample in measurement cell, or measurement cell internal volume
Mc = Mass of measurement cell
K = Constant
d
K
Vc
T
Mc
Vc
=
−
4
2
2
π
Supposing that the oscillating cycles Ta and Tw are obtained through measurement of reference
materials of known density (density da and dw), the facto value F is calculated as follows.
F
K
Vc
d
d
T
T
a
w
a
w
=
=
−
−
4
2
2
2
π
Accordingly, the density “d” of unknown sample can be calculated according to the following formula by
measuring its oscillating cycle T.
d d
F T
T
a
a
=
−
−
(
)
2
2
CANNON
®
D155 Density Meter Instruction & Operation Manual
Version 1.1b – August 2014; CANNON® Instrument Company
2139 High Tech Road • State College, PA • 16803 • USA