Hach Flo-Dar Sensor Basic User Manual page 10

Section 5 Installation
Explosion hazard. Trained personnel only must install or commission the equipment.
5.1 Mechanical installation
5.1.1 Site location guidelines
To prevent damage to the enclosure, install the instrument away from direct sunlight, ultraviolet radiation (UV),
heat sources and severe weather. Install a sun shade or protective cover above the instrument when the location
is outdoors.
For the best accuracy, install the sensor where the flow is not turbulent. The ideal location is in a
long, straight channel or pipe. Outfalls, vertical drops, baffles, curves or junctions cause the velocity
profile to become distorted.
Where there are outfalls, vertical drops, baffles, curves or junctions, install the sensor upstream or
downstream as shown in
that is at least five times the pipe diameter or the maximum fluid level. For downstream locations,
install the sensor at a distance that is at least ten times the pipe diameter or the maximum fluid level.
If the location contains a junction and the flow in one pipe is much higher, install the sensor on the
wall near the lower flow pipe.
Figure 4 Sensor location near an outfall, vertical drop or baffle
1 Acceptable upstream sensor location
2 Outfall
3 Distance upstream: 5 × maximum level
4 Acceptable downstream sensor location
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Figure 4–Figure 6. For upstream locations, install the sensor at a distance
5 Distance downstream: 10 × pipe diameter
6 Vertical drop
7 Baffle