Physical sensor installation, Preparation, Positioning the sensor – Xylem Oxix Dissolved Oxygen Transmitter User Manual
Page 20: Preparation positioning the sensor

20
GB Oxix Manual 080915
FW: 841013-009, 846001-002, 841513-009
Dissolved Oxygen Transmitter
Physical Sensor Installation
Preparation
Select a position that can produce a valid and representative measuring value
and provide sufficient space for physical cleaning of the sensor on a regular
basis.
Positioning the Sensor
The positioning of the sensor is very application dependant. There are, how-
ever, some "do"s and "don't"s that can be used as guidelines.
Do
In
•
aeration tanks or basins with significant fluctuation in depth the
sensor should be mounted on a foating device that keeps the sensor
submerged to a fixed depth from the surface.
In tanks or basins with no or little fluctuation in depth the sensor may
•
be mounted in a fixed position approximately 1/4 below the surface.
The optimal position at installations in flow-through aeration basins with
•
one measuring point is near the tank inlet.
The optimal positions at installations in flow-through aeration basins
•
with two measuring points are near the tank inlet and the tank outlet.
Don't
Do not position the sensor at or very close to the surface. Strong wind
•
aeration leads to increased dissolved oxygen concentration in the sur-
face layer which may not be representative.
Do not use a fixed sensor position in aeration tanks/basins with signifi-
•
cant depth fluctuations. The dissolved oxygen saturation varies with
the depth.