Hach BL9000 Bedienungsanleitung Seite 12

• Sediment—When sediment is in the flow channel and the flow calculation is based on area, the
control instrument uses the measured depth of the sediment to adjust the flow channel
dimensions.
• Level Adjust—The level adjust option sets the level value to the current head (the level that
contributes to flow) in the channel. Use the level adjust option for weir installations when the
bubbler line outlet is in the water. The level adjust value is the vertical distance from the zero
reference point to the water level. Level adjust values are positive when the water level is above
the zero reference point as shown in
reference point. In a circular pipe, the level that contributes to flow is the distance from the surface
of the water to the invert (bottom) of the pipe. In a flume the level that contributes to flow is the
distance from the surface of the water to the floor of the flume.
Note: When the user enters a value for level adjust, the control instrument erases the sensor offset value.
Figure 8 Weir with flow
1 Zero reference point
2 Level adjust value (head value that contributes to
flow)
• Sensor Offset—The sensor offset option is for applications where the bubbler line outlet is above
or below the zero reference point. Use the sensor offset option for weir installations when the
bubbler line outlet is above the water level. The sensor offset value is the vertical distance from the
bubbler line outlet to the zero reference point. Sensor offset values are negative when the bubbler
line outlet is below the zero reference point as shown in
outlet is above the zero reference point. The sensor offset option is also used in non-weir
applications when the bubbler line outlet is above or below the zero reference point of the channel.
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Figure 8, or negative when the water level is below the zero
3 Raw level measurement
Figure 9, or positive when the bubbler line