Abstract: A sampling system for drawing samples from a fluid flow which is responsive to manual actuation, predetermined increments of flow volume, or predetermined increments of time. The system includes a flow meter and a flow sampler interconnected and physically located in the vicinity of the flow being monitored. The flow meter converts the flow head to flow rate and subsequently to flow volume. The head to flow conversion is mechanical and provides for flow measurement through a flow channel having a given cross section shape over a wide range of shape sizes by means of an electrical adjustment. The flow meter provides for flow measurement through flow channels having varying cross secton shapes by means of selectively engaging a predetermined one of a plurality of cams designed to convert head to flow is being measured.