Product Overview - Hach BL9000 Manuel De L'utilisateur

Product overview

Connect the BL9000 bubbler only to the FL1500 flow logger. Connection to any other flow logger can cause
damage to the BL9000 bubbler and the flow logger.
The BL9000 bubbler is a level sensor that uses the bubbler method of level measurement. Refer to
Figure 1. The bubbler continuously pushes air through a tube (the bubbler line) that is installed in the
flow channel. The pressure in the bubbler line increases when the liquid level increases in the flow
channel. The bubbler calculates the liquid level from the pressure reading. The connected control
instrument uses the level reading, geometry and flow properties of the flow channel to calculate the
flow rate. Refer to Specifications
the BL9000 bubbler.
The bubbler uses a differential pressure sensor to compare the air pressure in the bubbler line to the
atmospheric pressure. The bubbler uses the pressure difference between the bubbler line and
atmospheric pressure to calculate the liquid level. At regular intervals, an internal valve connects the
two measurement ports of the differential sensor to atmospheric pressure and sets a zero value. The
zero operation adjusts for drift and temperature sensitivity of the differential pressure sensor.
The bubbler measures the liquid level (referred to as the "head") in an open channel and the
connected control instrument calculates the flow rate based on the head-to-flow relationship of the
primary device. A primary device is a hydraulic structure, such as a flume or weir, that has a known
level-to-flow relationship.
Note: As an alternative, the connected control instrument can calculate the flow rate based on the liquid level in the
channel and the velocity supplied by a velocity sensor.
Figure 1 Product overview
1 Mounting bracket
2 Clip to hold desiccant cartridge
3 Desiccant cartridge
4 Air inlet port
1
Refer to Replacement parts and accessories
N O T I C E
on page 3 for the possible control instruments that can be used with
5 Cable to control instrument
6 Bubbler line (user-supplied
7 Bubbler line connector
on page 17.
1
)
English 5