6
zero. It can accurately determine whether the polariser and the analyzer are in an orthogonal
position, identify the phase of f component alternating light intensity, and determine whether the
analyzer deviates from the orthogonal to the left or right position.
3.3 Instrument Structure
Figure 2
1-LED
6 - collimator
11 - aperture
16 - servo motor
21 - Power of
light source
2-receiving
aperture
7 - tube
12 - detector
17-mechanical
drive
3 - condenser
8 - analyzer
13 - Automatic
high pressure
18-yard drive
Count
4 - polariser
9 - lens
14 - preamplifier
19-SCM
5 - modulator
10 - filter
15 - Motor Control
20-LCD
Figure 2 is a block diagram of the instrument. The light emitted by the light-emitting diode passes
through the diaphragm, condenser lens, polarizer, a Faraday modulator and collimator in order, and
forms a beam of light which is vibration plane collimated and plane polarized, changing with voltage
alternating of the Faraday ring. The light goes through the tube with test solution, enters the
analyzer, and then passes through the receiving objective lens, filter and diaphragm. The
monochromatic light with wavelength of 589.3nm goes into the photomultiplier tube, which
converts the light intensity signals into electrical signals, and the light is amplified by the
preamplifier. The automatic high-intensity light is incident on the photomultiplier tube in
accordance with an automatic pressure change photomultiplier tube, in order to meet the
