Context
This article will help you understand how the force settings for the Robotiq Grippers work and how the force is measured.
Knowledge
The force setting defines the final gripping force for the gripper. The force will fix the maximum current sent to the motor. If the current limit is exceeded, the fingers stop and trigger an object detection notification.
So on the settings of the gripper, the force sent is not really the force, it's the current sent to the gripper.
The real force in Newton, cannot be measured with our gripper as we don't have any sensor on it. The force will be an approximation of the force, but it's not linear and depends on many parameters.
The current depends on the force parameter applied, the speed but also the type and material of fingertips, the material of the object to take, the inertia of the gripper ...
Here is some graph available on the documentation of the 2F Gripper, that shows some test done with some different objects with some different settings on force and speed :
So if you need some really precise force to apply, we recommend making some tests of speed and force to verify the real force applied on the object.