ATAGO 5050, Instruction Manual

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5. Scales
ANGLE OF ROTATION - denoted by "α" and expressed in degrees ("° ")
The rotation of polarized light is observed when polarized light that is oscillating unidirectionally rotates as it passes
through a liquid. The measurement of the angle of such rotation is called the "Angle of Rotation."
The angle of rotation is the basic numeric value measured by polarimeters and are dependent on the concentration
of the liquid, the length of the observation tube, temperature, and the measurement wavelength.
The instrument measures angle of rotation equivalent to a 20mm observation tube and displays angle of rotation
converted to 100mm observation tube and 200mm observation tube.
SPECIFIC ROTATION
- Denoted by "[α]" and expressed in degrees ("° ")
The Specific Rotation is a numeric value unique to each substance. By definition, the specific rotation value is equivalent
to the angle of rotation obtained by a measurement using a solution of 100% concentration in a 100mm observation tube
(although such a measurement is actually not practicable). The specific rotation is determined by the following formula:
Specific Rotation = (10,000
×
Angle of Rotation)/(length of observation tube [mm]
×
Concentration [g/100mL]
*1
)
*1
m
To measure the specific rotation, input the concentration value of the
※1
m
sample to be measured into the instrument before taking a measurement. (
r
page 12)
CONCENTRATION - Expressed in g/100mL
The Concentration is the density of an optically active substance dissolved in water or alcohol. The concentration is
determined by the following formula:
Concentration = (10,000
×
Angle of Rotation)/(length of observation tube [mm]
×
Specific Rotation
*2
)
*2
m
To measure the concentration, input the specific rotation value of the
※2
m
sample to be measured into the instrument before taking a measurement. (
r
page 12)