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INTRODUCTION
Monochromatic rays from Infrared LED with 589.44nm wavelength travels through condenser,
lens, polarizer, modulator and collinator to form a plane polarized light. The plane of polarization
caused by the alternating current which flows through the Faraday coil at a particular frequency.
This polarized light then passes through the sample tube containing the solution to be measured
and then through the analyzer, lens, filter and an aperture before falling on the photomultiplier
detector.
The light falling on the analyzer deviates from the optical zero position (with reference to the
polarized light) to the extent of optical rotation of the sample and the photomultiplier detector
output will produce an electrical signal with the frequency corresponding to the optical rotation
of the sample. This signal after passing through the selective frequency amplifier and power
amplifier drives the servo‐motor & in turn the analyzer through a mechanical gear assembly until
the optical zero position is regained.
After switching 'ON' the polarimeter, without the sample in the compartment the analyzer will
stabilize at a position (optical zero position). When the sample with the optical rotation is
placed in the sample compartment, the light falling on the analyzer deviates by angle from the
optical zero position and hence the analyzer is rotated by angle through the servo motor
coupled mechanism to get a new optical zero position. This rotation is measured through an
encoder and is displayed on the digital readout.
The high voltage supplied to the photomultiplier tube varies in proportional to the intensity of
light falling on it and hence this instrument is able to measure dark samples with transmittance
upto 1%.
SPECIFICATIONS
Light Source
Wave length
Modulator
Measuring range
Optical Rotation
International Sugar Scale : ‐120 ~ +120 Z
Accuracy
Optical Rotation
International Sugar Scale : +(0.03 Z+ measuring value x 0.05%Z)
Minimum transmittance of sample : 1%
Power Supply
Dimensions
Weight
: Infrared LED.
: 589.44nm
: Faraday magneto optical modular.
o
o
: ‐45 ~ +45
o
o
o
: +(0.01 + measuring value x 0.05%)
o
: 230V, +10% AC, 50/60 Hz
: 600mmx320mmx240mm
: 30kg
1
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