linear transducer velocity measurement

[alanled]

Having a few problems with this one!!

I have a 0-10v Linear transducer which is attached to a hydraulic cylinder which in turn is controlled by a proportional flow control valve. Normally in this application I would use a flowmeter to provide feedback to the proportional valve but unfortunately i dont have one. Im trying to convert the 0-10v linear transducer signal to give a voltage output depending on the velocity of the signal, is this possible? I've had a look through the examples to no aval' 

Any pointers would be of great help. Many thanks folks.

[Ray.R]

If I understand correctly, you want to measure the floe rate of a fluid going through a pipe, but cannot use a flow meter. 

How do you intend to use a linear transducer?  Are you measuring the valve opening and deduce a flow rate from it?  How do you deal with pressure variations?  and anything that may be affecting flow upstream?

[alanled]

Thanks for your interest Ray, The hydraulic cylinder is moving quite slowly about 50mm/min but the load on the cylinder is increasing, so if I provide the flow control valve with a constant signal voltage  the cylinder will start to slow down thoughout its travel. As I said, normally I would use a flowmeter to provide feedback, pressure is not a problem. I think what Im trying to do is some how count the rising voltage from the linear transducer and measure the pulse width to give an output that I can input into a PID block along with a setpoint for example 5mm/min and the proportional valve will open enough to maintain the cylinder a t that speed.