Teledyne T802 - page 222

Principles of Operation Teledyne API T802 Paramagnetic O2 Analyzer Operation Manual
220
Figure 12-1: Paramagnetic O2 Sensor Design
When sample gas containing oxygen flows into the magneto-mechanical sensor,
the O2 molecules are drawn toward the strong point of the magnetic field. This
causes the N2 filled spheres to deflect even more so that the suspended dumbbell
body pivots on the platinum wire. The more O2 present the further the dumbbell
body is deflected from its neutral position.
The position of the dumbbell is detected by a pair of photocells that receive a
light beam reflected from a mirror attached to the center of the dumbbell body.
As the dumbbell body pivots, the angle of the reflected light beam on the
photocells changes. The resulting potential difference creates a current.
Light
Source
Photocells
Coil
Figure 12-2: Paramagnetic O2 Sensor Block Diagram
07275B DCN6418