What kind of embolism - after cavitation or in the cut plants, like flowers?

Both of them please...but my main project is about cut flowers...

This is more difficult.

Cavitation can be "heard" so You can evaluate its intensity by sound sensors.

Good results are obtained by crio-TEM or SEM microscopy.

There were also attempts to show embolised vessels by using some ink.

All of above are methods which destroy the plants - You have to cut samples.

this method is for short time and it's not economical in wide scale.. I want to inhibit this phenomenon for long time and also I need a method for inhibition the xylem embolism for flower before cutting...

I think to get some postharvest effect the only good and feasible way is to hydrate well your plants from which you cut off the floral stalks. Just after picking the flower stalks I would recommend place the cut flowers immediately in a pulse solution - depending on the species you have to be carefull with the sucrose concentration (some respond negatively to high sucrose concentrations). In the maintenance solution you have to have an acidifier (to keep pH low so to bacteria populations in the solution low) and/or bactericide and with some sucrose so can have a good and adequate shelf life.