The amount of flow has no real correlation with the level in the flume (Ha), instead is a factor of up stream restrictions. In order to accurately track flow during a submerged flow condition, the entire installation must be evaluated. Once this evaluation is completed, and the cause and effect of up stream flow limits are identified, a separate flow curve should be developed for submerged conditions. This curve should correlate the submerged state, expressed as a percent (Hb/Ha), with an effective flow rate, expressed as a percent of the calculated flow rate based on the level at Ha. The Inventron (dual input) system is programmable, and will accept a table defining the effect of submerged flow for a given installation. The layout of the table is as follows:
The percent of submergence may start with any value between 0.00% and 100.00%. The increments between table entries do not need to be equal, but each entry in the table must have a percent of submergence greater than the proceeding entry. This allows you to concentrate table entries at critical areas of the of the flow curve.
The flow adjustment values normally start at 100.00% but may be any value between 0.00% and 100.00%. The final table element does not need to be 0.00%, you may program the unit to continue to show a flow, even at 100% submergence. This will be dependent on your installation, and any limit on flow down stream.