The PF-400J plasma focus device (400 J of energy) was studied in a similar way to a pulsed source of high-energy x-ray radiation. High-sensitivity fast-response commercial radiographic film and different metal filter array combinations were used to study the energy of the proper emitted x-ray. The effective energy of the hard x-ray radiation is studied and discussed in terms of its effective mean attenuation with the penetration distance on different metallic samples when the x-ray pulsed beam is supposed monoenergetic. These results were then used to assess the energetic properties of the pulsed radiation when different x-ray film-filter array combinations were irradiated between tens to almost 160 effective pulses of x-ray coming from the PF-400J device.