Experimental validation of non-contacting measurement method using LED-optical displacement sensors for vibration stress of small-bore piping

•A proposed non-contacting measurement method for piping vibration was verified.•The applicable conditions of the proposed method were clarified.•The influential factors on the application of the proposed method were shown.•The applicability of the method was discussed from the viewpoints of S/N ratio.•The practical use of the proposed method was experimentally demonstrated.