Need 10 mL/min or more for accurate measurement
In case water flow is not enough, water stays on the same area and water quality may go bad. And, air bubble or impurities may stick on the probe, and the measurement would be be accurate. Make sure the flow rate to be 10mL/min or larger
Proper flow direction
This is the example of installation. Avoid from getting air bubble or impurities remained on the probe.