Hi,

You need to measure the pump flow for different rpm values. Then, you must do a "calibration curve" of flow v/s rpm. It must be straight line (Flow= m* rpm + a). After that, use the calibration curve to determine the rpm needed for your purposes. rpm= (flow-a)/m

I assume you can manipulate the rpm of the pump. If you don't. You need a variable frequency drive (VFD).

All the best,

carlos

Hi,

My suggestion would be that you'd better calibrate the flow rate at the working condition. The flow rate can be easily influenced by the property of the fluid, the type of tubes, type of pump head as well as the pressure in the reactor, etc. Principally, it is almost impossible to make a precise (but approximate) standard curve by off-line calibration.

To calibrate the flow in-line, you can link a burette (sterilized) between the pump and your feed solution using a three ports connector. You will be able to calibrate the flow in exact ml/min (or any other unit you prefer). The calibration process will not influence the feeding process neither . 

Let me know if you got further questions.

Best

dear Musfique

first of all you have to calibrate the pump and plot a calibration curve then you will have a plot that presents flow rate vs. rpm. 

regards

I agree with the other answers. You should first calibrate the pump at different RPM and therefore calculate the pump speed using the calibration equation.

Best,

Xavi

I have met the same problem. How do I calibrate the flow rate at the working condition and keep the system still working at same time?

Hi

I am facing the same problem with my pump, I think I will try the calibration method suggested above.