Gas Flow Chart; Figure 4 Gas Flow Chart - M&C PMA Series Instruction Manual

The measuring cell consists of two nitrogen-filled spheres  which are arranged in the form of a
dumbbell. In the dumbbell's central point of rotation, a small mirror  is placed. The dumbbell is sur-
rounded by a wire coil needed for the compensation procedure. The described system is fixed rota-
tionally symmetrical inside a glass tube via a tightening strap out of platinum  and is screwed up with
two pole pieces .
Two permanent magnets are producing an inhomogeneous magnetic field. When oxygen is flowing in,
the molecules of the oxygen are drawn into the magnetic field. In consequence, the lines of electric
flux on the cuneiform pole pieces  are compressed. The nitrogen-filled diamagnetic spheres are
pushed out of the magnetic field. This causes a rotation of the dumbbell. The rotation is detected via
an optical system consisting of mirror , projection LED  and photoelectric cell .
In case the dumbbell is pushed out of the magnetic field, the tension of the photoelectric cell is imme-
diately changed. The measuring amplifiers  and  are producing a respective current which devel-
ops via the wire coil on the dumbbell an electro-magnetic load moment. The load moment is resetting
the dumbbell into its zero position.
Every change of the oxygen concentration produces a linear proportional change of the compensation
current and can be read directly in % O
Due to its very small stagnant volume (2 cm
tremely fast response time (T
11

GAS FLOW CHART

Figure 3 shows the gas flow chart of the oxygen analyzer PMA 45K1.
Sample gas outlet,
Tube fitting 1/8"
Sample gas inlet,
Tube fitting 1/8"
1 Analyser housing
2 Measuring cell
Figure 4 Gas flow chart
12
as oxygen value on the display .
2
3 ) and the direct flow of the M&C measuring cell, an ex-
-time) of 1 second for a high gas flow can be realized.
90
1
1/8" stainl.steel
PMA45K1 | 1.00.01
2
tube
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