| 摘要 |
A method and apparatus for determining liquid flow through a system including a container from which liquid is pumped out by one or more pumps, the pumping rate for all combinations of pumps being known and stored in a memory. When pumping is off, the liquid surface rises from a lower to an upper limit level. When the surface reaches the upper limit level, the pumping phase begins. When the surface reaches the lower level, the pumping is stopped and the cycle is repeated. If only one pump is required, the inflow rates prior to and just after the pump cycle are averaged. This average flow rate is multiplied by the pump time and added to the totalizer. Then the container volume is also added, following which the outflow rate (pump rate) is calculated by using the previously established average inflow rate (total volume divided by pumptime plus the average inflow rate). This value can be stored in the addressable memory. If a plurality of pumps is required to make the liquid level drop, the liquid volume pumped during the pumping phase is calculated from information in the memory to determine the stored volume pumping rate for the particular operating pumps, and multiplying such stored rate by the duration of the pumping phase. The result is then added to the totalizer.
|
