Introduction
13
Waltron User Manual
9065 Luminescent Dissolved Oxygen Analyzer
2.2
SENSOR
The bottom of the sensor housing provides the location of the dissolved oxygen sensor, shown in
the figure below.
Figure 2.2: 25 mm Sensor.
2.3
COATINGHOLDER
The 9065 coatingholder is recognizable by its hexagonal shape.
Figure 2.3: 9065 Coatingholder.
2.4
O
2
MEASUREMENT PRINCIPLE
The O
2
measurement is based on measuring the luminescence of a layer that is sensitive to
oxygen. The luminescence changes according to the partial oxygen pressure. The quantity of
dissolved oxygen gas in the liquid is calculated with the aid of the measured partial oxygen
pressure and the temperature.
The oxygen sensor optically measures the liquid’s O
2
content based on the luminescence
measurement principle, where an oxygen-sensitive layer is exposed to blue light. As a result,
molecules in the oxygen-sensitive layer are excited.
In the absence of oxygen, the molecules light up red. In the presence of oxygen, the oxygen
molecules collide with the molecules in the oxygen-sensitive layer. The molecules that collide
with oxygen no longer light up. Through this process, a link is created between the oxygen
concentration and both the light intensity and the speed at which the light intensity is reduced.
The light intensity reduces when the oxygen concentration is higher, whilst the light intensity
reduces at a faster speed.
Coatingholder
Temperature