• With the ABS solution the measurement of the overflow can be made without an external flow meter. The measurement is done with the pump controller and it’s sump level sensor, only a cheep level switch is needed.


• An alternative method to measure the pump capacity is to calculate the volume of water in the pump sump each second when no pump is running. The difference in volume will correspond to the station inflow in l/s. This measurement is made by the pump controller only using the pump sump level sensor; hence the external flow meter is not needed. The calculation of the volume in the sump is made from the level and the shape of the station. The shape is entered into the controller by giving the area at each breakpoint in the sump including the bottom.

• When a pump is started the calculated inflow is assumed to remain constant during the pump capacity measuring period, which normally is about 30 seconds. When the pump is started it will cause the volume change in the sump to change. This change will correspond to the outflow of the station and of course also the pump capacity.

• The principle is to use the same level sensor both for measuring the level in the pump sump and the level in the overflow weir. Since the overflow zero point is at a quite high level from the sump bottom, often several meters, the drift and temperature errors of the level sensor will have a significant impact of the measuring accuracy. To correct for these errors, a level switch is placed exactly at the point where the overflows starts giving a signal to the controller “Here overflow starts”.


• Since the duration of an overflow normally is short there will be no drift impact of from the level sensor during the measuring.

• This solution will give a integrated, very cheep and very accurate measuring of the overflow.

• Also it is containing very few parts resulting in less possibilities of breakdown.