MEASUREMENT
The thrust of the spring is measured with a special dynamometer at a room temperature of approx. 20 °C with the rod compressed by about 10 mm and free from friction by the seal.
The measurement is given in kg and is a “static” value normally referred to when defining the characteristics of a spring. Other components interact with this basic value and become especially noticeable in the “dynamic” phase of the spring. We are referring in particular to the friction produced by seals and rod supporting guides.

The resistance exerted by such friction acts in the opposite direction to the rod movement, it has a value of approx. 2/3 kg and is added to or subtracted from the above-mentioned “static” thrust.
The closing force is indicated in the graph by F0 and the opening force by F1.
It can be seen that F0 and F1 are higher and lower respectively than the average line which identifies the “static” thrust force (FM).

THRUST
The thrust of a gas spring is determined by the pressure that the nitrogen in the cylindrical body exerts on the section of the rod. By suitably assembling rods of varying cross sections with bodies of suitable volume, by acting on the gas input pressure and adjusting the channels on the rod or by introducing a greater quantity of oil, various operating configurations of the gas spring may be obtained in addition to the required thrusts in order to satisfy a wide range of user requirements.