Flow sensor

Hi,

I have just installed a Flow Sensor (5000 l/hr) and the readings are incorrect. For example, if I have the pump set to its lowest power the flow reading is 1119 l/h and when set to the highest power the flow is 699 l/h.

A few extra details below:
I am testing it with fresh water.
The sensor is setup with the water flow going in the same direction as the arrow on the sensor.

Attachment 13736

Lowest pump power

Attachment 13734

Highest pump power

Attachment 13735

Flow Sensor settings

Attachment 13733

Thanks,

James