RADIUS GAUGE FOR INTERNAL CIRCULAR ARC

The utility model is used to directly measure the internal circular arc in the usual range. The utility model has the advantages of convenient portability, convenient operation and high precision. The utility model is a radius gauge for internal circular arc which is suitable for use in the field to directly measure the internal circular arc, particularly measure the internal circular arc with the centre angle smaller than 180 DEG. The radius gauge for internal circular arc solves the problem that the production field has no instrument to measure the internal circular arc with the centre angle smaller than 180 DEG. The utility model has a main scale and two auxiliary scales which are matched with each other, and the structure is more simple than the prior instruments, such as the universal tool microscope, the saddle gauge, etc. The two identical and crossed auxiliary scales attach the surface of the internal circular arc, and the crossing point of the two auxiliary scales is adjusted to make the scales equal. The main scale is used to directly measure the distance from the crossing point of the two auxiliary scales to the internal circular arc, and the instance is the radius of the internal circular arc. The spare parts with different lengths are combined and adjusted to enlarge the range of measurement, and the scale is additionally provided with a vernier.