The JJF 1312-2011 standard applies to the calibrating of the Shore Shore Durometer Type AO. The Shore Shore Durometer Type AO is mainly used for Hardness measurement of low Hardness vulcanized rubber and thermal plasticity rubber. This specification specifies the calibrating procedures and requirements for the Shore Durometer Type AO to ensure the accuracy of measurement results. The cited literature includes international and national standards such as GB/T 531.1-2008 and ISO 18898:2006 covering the Measuring method and verification procedures for the Shore Shore Durometer. The specification details the structure and Measurement principle of AO type Shore Shore Durometer, including the functions and usage of the pressure needle, pressure foot and its measurement mechanism, which provides the basis for the accurate calibrating of the instrument.