Mounting on the ceiling of the sewer

For installation on a sewer ceiling, the Ceiling mount for pipe (400417) can be used, provided that the sewer runs straight for several metres. The bracket can accommodate both a velocity sensor and a level sensor. The front of the mount, where the velocity sensor is located, serves as a protective shield and protects the sensors from foreign objects when the sewer is temporarily completely filled. However, due to the direction-bound design of the mount, the velocity sensor can only be operated against the direction of flow.

Installation on the ceiling of the sewer (schematic representation)

Due to the fixed angle of 45° of the mount for the velocity sensor and the absence of joints, the Ceiling mount for pipe offer little flexibility in the alignment of the sensors. However, this makes them less sensitive to changes in sensor alignment due to external influences during operation. The Ceiling mount for pipe fastened using three hanger bolts, each of which is clamped between two nuts. The nuts located on the side of the sewer ceiling enable the adjustment of the alignment, while the opposing nuts serve to secure the mount. A detailed description of this procedure can be found in chapter Fixed mounts.

Important: Please note that the mounting height also determines the horizontal distance between the mounting point and the point at which the velocity is measured. This is particularly important if both a velocity sensor and a level sensor are installed in the bracket. The two sensors perform their measurements at different points in the channel. The greater the mounting height, the further apart these measuring points are. In this case, the minimum permissible mounting height is determined by the block distance of the level sensor. The greater the mounting height, the further apart these measuring points are. In this case, the minimum permissible mounting height is determined by the blocking distance of the level sensor.

Position of the measuring points

Offsets of the sensors

x Horizontal distance from the level sensor to the velocity sensor (113 mm)
y Vertical distance from the level sensor to the velocity sensor (29 mm)
h Mounting height
d Distance between the measuring points (Level and velocity

d = h + x + y

Installation on the ceiling of the sewer

1 Nut for locking in position 5 Sensor holder (ceiling mounting)
2 Nut for adjusting alignment 6 Flow velocity sensor
3 Hanger bolt 7 Level sensor
4 Protective shield (part of the sensor holder)    
  1. Drill three holes with a diameter of 12 mm and a min. depth of 70 mm at the positions shown in the illustration Hanger bolts installed in the duct ceiling. To determine the positions for the drill holes, you can also hold the sensor mount against the ceiling and transfer the holes. To align the sensor mount parallel to the flow and centrally above the channel, we recommend using a cross-line laser. The sensor mount has milled recesses around the level sensor mount and on the outer edges, which serve as reference points for alignment using a cross-line laser.
    Note: Pay special attention to the parallel alignment with the flow, as it is no longer possible to adjust the sensor mount on the vertical axis. If the duct may temporarily be filled to capacity, the bracket should also be mounted so that the flow first hits the side where the protective shield is located.
    Tip: The intersection of the lines passing through the reference points defines the position at which the level is measured. The point at which the flow velocity is measured lies on the extension of the longitudinal axis. The distance between the measuring points (level and flow velocity) is determined by the mounting height and can be calculated as specified above.

    Determining the position for the drill holes

    1 Sensor holder (ceiling mounting) 3 Laser cross of the crosshair laser
    2 Protective shield (part of the sensor holder) 4 Milling (reference point)
  2. Insert a wall plug (included in the scope of supply of the mounting bracket) into each of the drill holes. Then screw the hanger bolts (also included in the scope of supply) into the wall plugs.

    Installing the hanger bolts in the duct ceiling

    Hanger bolts installed in the duct ceiling
    1 Hanger boltM10x100 mm (included in the scope of supply of the mounting bracket) 2 Wall plug 12x70 (included in the scope of supply of the mounting bracket)
  3. Attach the sensor mount to the hanger bolts installed in the duct ceiling using the nuts supplied with the mounting bracket. The sensor bracket is clamped between two nuts. This mounting method allows the sensor bracket to be adjusted in all directions.

    Attaching the sensor mount to the hanger bolts

    1 Hanger bolt 3 Nut for locking in positionM10 (included in the scope of supply of the mounting bracket)
    2 Nut for adjusting alignmentM10 (included in the scope of supply of the mounting bracket) 4 Sensor holder (ceiling mounting)
  4. Insert the BLE Radar into the level sensor holder and align it correctly. Detailed instructions are provided chapter Fixed mounts.