i am having a pneumatic cylinder no.1 whose piston is connected to another cylinder no.2. the cylinder no2. sucks the oil from its inlet port with return stroke of cylinder no.1 and delivers the same from its outlet port with forward stroke of cylinder no1, as both are coupled together. now i want to know that if, i am connecting the stroke of the cylinder no1 to a LVDT, can its displacement be used to know how much fluid has been delivered from output port of cylinder no2. my idea is that if i am using a signal conditioner with ADC converter and configuring it with a MMI, i can get the exact volume displaced in MMI if i am multiplying the output voltage of LVDT (displacement of cylinder's stroke) with a multiplier which id the function of displacement of cylinder's stroke, converted to volume of oil displaced? WOULD MY IDEA WORK. AND HOW ACCURATE WOULD BE THE VOLUME MEASURE? ACCURACY IS MORE IMPORTANT TO ME.

 

Why do you care about accuracy with such a crude measurement technique?

It seems like the technique is entriely dependent on whether the same amount of oil is delivered each stroke. I don't know if that is
realistic or not.

--
Bob

 

This is the principle behind many common metering pumps. A cylinder and piston will always deliver a known volume as long as you can accurately measure the piston stroke length and rate (rpm of the motor connected to the piston). In fact the lvdt isn't even required unless you plan to use a controller to change the stroke length during operation. See here

So the answer to your question is Yes, this measurement technique is very accurate and has been used for many years. Common uses are for measuring very low amounts of chemical or dye additions into a process where the rates of flow are too low for flow meters to be effective.

Rob
www[.]lymac.co.nz

 

Though of course, if you plan to reverse this technique and turn a pump into a flow meter I think you will find that the losses and inefficiencies will mean it doesn't work.