The safety testing of explosives involves the determination of various properties of the different energetic materials that are used in commercial, mining, and military applications.
It would be very difficult to provide an absolute scale for sensitivity with respect to the different properties of explosives.
PETN may be detonated by striking with a hammer on a hard steel surface (a very dangerous thing to do), and is generally considered the least sensitive explosive with which this may be done.
Another explosive that is used as a calibration standard is TNT, which was afforded the arbitrary Figure of Insensitivity of 100.
Therefore, an experienced ordnance technician who works with raw PETN will know that the new explosive is not as sensitive with regards to impact.