The DRYCAP® sensor is not sensitive to flow rate. Whether installing the probe directly in the line or sampling the air out, for best measurement performance and response time we recommend a minimum of 1 liter/min (2 scfh). Installation in higher flows is acceptable as long as the process pressure remains stable (since dewpoint is highly pressure dependent, a change in pressure at the measurement point will change the dewpoint reading).
When using the DSC74 sample cell to extract an air sample from the process, a 1 liter/min flow can be approximated by first closing the leak screw (turn screw clockwise all the way in until tight), then opening the screw by turning counter-clockwise 1/2 turn.