Instruction ManualOCM Pro CF®OCM Pro CF - Rev. 07 as of 04.12.2012 Page 79Sludge level The sludge level set is considered during calculation as non-moving sub-areaon the channel bottom and will be subtracted from the wetted hydraulic totalarea prior to performing flow calculation.Low-flow volume Qmin This parameter serves to suppress lowest movements or apparent volumesarising. Used mainly to measure overflow volumes in constructions which arepermanently flooded by receiving water.Qmin: measurement values lower than this one will be set to >0<. Only positivevalues are allowed to be set. These values are going to be considered as abso-lute values and therefore have positive as well as negative effects.Vmin: low-flow volumes in applications with large profiles and filling levels can besuppressed by means of this parameter. Lowest velocity fluctuations withinlonger periods of time may cause apparently large volume fluctuations whichcannot be gated by using the value of Q min.Flow velocities below this value will be set to „0“ which will set the calculatedvolume to „0“ as well.Only positive values can be set. These values are going to be considered asabsolute values and therefore affect positive as well as negative velocities.Both setting options of low-flow suppression have an > OR< relation betweeneach other.Fig. 8-29 Selection low-flow volumesThe suppression of low-flow volumes is no offset but a limit value!8.4.2 Parameter Menu “Level “Fig. 8-30 Menu level measurement
