Testing instrument

The measuring instrument is composed of a DC double arm bridge with accuracy above 0.2 level and accessories. Micrometer or scale shall be used for measuring the size of Lantern rivet, and the indication value shall not exceed 0.5mm. Vernier caliper shall be used for accurate diameter measurement of core pulling rivet, with precision of 0.01mm

Specimen

There should be no cracks or other defects on the surface of the cable, and it should be smooth and clean without oil stains and air oxidation layer. The cable diameter transformation of the cable should not exceed 1%

Accurate measurement of raw materials for blind rivets

The vernier caliper is used for the accurate measurement of cable diameter. The two sides and the middle of the test piece are respectively measured in two vertical directions. The arithmetic average value is taken, and then the average value of the cross-section diameter at three locations is taken, The precision measurement of relative density is carried out according to JB / t7780.1-1995. When the special fixture is used to accurately measure the length of the specimen, the special-shaped rivet is used to continuously correct the distance between the two potential difference ends of the parallel surfaces on the fixture with a micrometer. When measuring the length with a ruler, the data error should be less than 0.2%

After the core pulling rivet specimen is fixed in the fixture, it is necessary to carefully and carefully measure whether the route is accurate. The accurate measurement can be carried out by adjusting the zero position of the galvanometer. The working temperature for accurate measurement is 20 ± 10 ℃