METHOD OF CHECK OF VALUE OF ELONGATION OF FLAT FIBRE-CONTAINING MATERIALS UNDER MECHANICAL DEFORMATIONS Russian patent published in 1997 - IPC

FIELD: measurement technology. SUBSTANCE: proposed method of check of value of elongation is nondestructive and suitable for current check in process of manufacture. Essence of invention consists in illumination of tested material with parallel light beam perpendicular to its surface and in registration of luminous fluxes Φ₁ and Φ₂ scattered by material in reverse direction in two similar solid angles oriented in mutually perpendicular planes under equal angles to incident beam. In this case one of luminous fluxes Φ₁ is registered in plane coinciding with direction of application of stress and axis of photodetector. Value of elongation of material is evaluated by value of coefficient of optical isotropy. EFFECT: enhanced authenticity of method. 3 dwg