Hach BL9000 Manuel De L'utilisateur page 13

Note: When the user enters a value for sensor offset, the control instrument erases the level adjust value.
Figure 9 Weir with no flow
1 Zero reference point
2 Sensor offset value
Calibration preparation
The bubbler level measurement is calibrated at the factory, however a user-calibration can be
beneficial for site conditions where the bubble rate, bubbler line length, water temperature or
composition have an effect on the measurement. To calibrate the bubbler, measure the depth of the
water at the installation site, then enter the depth in the calibration menu of the connected instrument
(or FSDATA Desktop, when applicable). Use the connected instrument or FSDATA Desktop to take a
measurement manually to see if the level reading after calibration is correct.
Note: Calibration erases the settings that are currently in the connected instrument for calibration, level adjust or
sensor offset.
Calibration at the installation site gives the best accuracy. If calibration at the installation site is not
possible, calibrate the bubbler as follows to keep the effects of friction and water density on the
calibration to a minimum.
3 Liquid level below zero reference point
English 13