Haloo,

is it possible to measure force with the pressure informations from inlet and outlet of a double acting cylinder? Or is there any additional sensor needed to measure force? thanks for the answer..

You can calculate the force imbalance ( difference ) between the cap end and rod end.

Pick units of area and pressure to suit yourself.

Force in cap end = area of piston * pressure in cap end.
Force in rod end = ( area of piston - area of rod ) * pressure in rod end.

The force imbalance is the difference between to the two answers.

Regards Woody

This message has been edited. Last edited by: Woodygb,

There are two more practical things to consider
1. If you are trying to measure force when moving you should mount the pressure transducers at either end of the cylinder where the flows will be lower. To many take the easy way out and mount the pressure transducers in a manifold or some other place where the flows are high when moving. The turbulence and Bernoulli effects interfere with the pressure readings.

2. An offset if often needed especially when the system is vertical. For instance a press will read a negative force while it is up because the rod side pressure will need to support the die of the press. A simple offset will take care of that.

The breakaway/frictional force can be computed/measured too by getting the breakaway/frictional pressure... It is the lowest amount of pressure at no load wherein the cylinder starts to move.

This is done frequently on forklifts and loaders to measure the load while driving. They are good to ~5% in these applications if the calibration has been done using the same procedure that the machine operator will. Part of the error is cylinder stiction. Part of the error has to do with electronic filtering, without which the numbers will bounce so much you can't read the number.

So...if you consider the issues Peter and Maglub brought up, it depends on your required accuracy and application.

ISZ