Air Flow Step Callibration
Dr. Peter Krenzke, Dr. Luke Venstrom
Mechanical Engineering and Bioengineering
A Cobalt Oxide oxidation experiment will involve alternating flows of Nitrogen gas and air. It is desirable for the flows to change as quickly as possible, to prevent cross-contamination. A test was run to confirm that the flow control system’s regulating valves would be sufficient. Air flow was sent into the system at 1 L/min using an MKS G-series flow controller. The flow was increased by activation of the flow controller, or by opening and closing the valve, which redirected air out of the system. Flow rate was measured using a filter-pressure transducer system. To calibrate the filter as a flow meter, it was attached to a Gilibrator, manometer, and compressed air outlet. Pressure in the system was increased, and air flow and pressure drop across the filter were measured. Pressure drop and flow showed a linear relationship, with an R2 value of 0.999, indicating laminar flow. A pressure transducer was added to the system and calibrated. In the flow system, voltage from the transducer was read and converted to flow rate using the calibration curves. When using the valve, air flow increased from 0 to 1 L/min in 20 milliseconds, but when using the flow controller, it took 200 milliseconds. Additional tests at 0.5 L/min showed longer times for both, with the valve increasing in 90 milliseconds, and the flow controller in 660 milliseconds. Shorter times for the valve indicate that they are preferable to activating the flow controllers for this experiment.
Haw, Gilbert D.; Anderson, Elias J.; Miller, Trent; and McDonald, Matt, "Air Flow Step Callibration" (2022). Summer Interdisciplinary Research Symposium. 127.