Instruction Manual 2009
Rev 3
DFS2 Doppler Flow Switch
4
Mounting The Transducer
a)
Select a location for mounting the sensor at a point where the flow profile is fully
developed. Generally the principle of 10 pipe diameters of straight pipe upstream,
and 5 pipe diameters downstream will suffice, but should valves or bends exist
upstream of the sensor, the amount of straight pipe immediately upstream will need
to be increased.
b)
Ensure that the sensor is mounted as far as
possible from potential noise sources, such as
pumps, control valves etc. and mount the
sensor at approximately 3/9 o’clock on the pipe
(if horizontal) to avoid errors due to air pockets
on top, or sediment at the bottom of the pipe.
c)
Either vertical or horizontal pipe runs are acceptable for sensor mounting.
d)
Before attaching the transducer head to the pipe surface, an area slightly larger than
the flat surface of the transducer must be cleaned to bare metal. (A small amount of
pipe pitting, even with spots of paint or rust, will not cause problems).
e)
The transducer must be mounted accurately, parallel to the pipe axis, for correct
performance, and transducer to pipe contact should be along the centre line of the
transducer head.
f)
Bonding to the pipe is achieved with silicone
coupling compound. Be sure to fill in any air
gaps that may remain at the pipe transducer
interface with additional compound.
A pipe clamp kit is included with the flow switch.
It includes silicone coupling compound, a
Neoprene rubber pad, and four polyamide 12
straps for pipe diameters up to 300 mm. In
applications with excessive vibration it is
recommended that the Neoprene rubber pad is
inserted between the pipe and the transducer.
Coupling compound must be applied to both
sides of the pad.
Mounting the Switch
The DFS2 electronics is housed in a water resistant housing, which should be
mounted in a location where the ambient temperature is within the range stated in
the specifications i.e. -10
°
C to 50
°
C.
3 O’CLOCK POSITION ON PIPE
IF HORIZONTAL
GOOD