NON-DESTRUCTIVE METHOD OF STRESS MEASUREMENT IN OBJECT SURFACE LAYER AND STRESS GAUGE Russian patent published in 2014 - IPC G01L1/24 

FIELD: measurement technology.

SUBSTANCE: invention refers to measurement equipment and is applied to determine mechanical stress in surface layer of an object. Method involves direction of unfocused visible range radiation flow of any intensity onto the test surface and registration of reflected flow by photodetector, comparison of the result with reference value obtained with known mechanical stress, temperature and surface layer roughness values for this radiation source. Stress gauge includes laser, defocusing devices for beam directed onto the test surface and focusing devices for flow reflected by the surface; photodetector of reflected signal; photodetector signal amplifier; comparator comparing voltage supplied by the amplifier with variable voltage of generator and generating voltage pulse; AND circuit encoding comparator pulse to short pulse string of reference frequency generator; temperature measurement unit; test surface roughness measurement unit; reference code storage device; digital comparator comparing signal obtained from the test surface with reference signals obtained with definite temperature and roughness; indicator displaying stress value for the test surface.

EFFECT: voltage determination in surface layer of examination object.

2 cl, 2 dwg