Process the benchmark. In the filter press used in parts processing, measurement and assembly process of benchmark benchmark called process. Can be divided into, measurement criteria, process datum and position datum assembly benchmark.

①Locating datum. Locating datum refers to the parts in the process of machining, used to determine the position of the parts on the machine or jig benchmark. It is a part of direct contact with fixture locating element points, lines or planes. As shown in figure 1-5, finish turning gear of large cylindrical, in order to ensure that they demand to the hole axis of A circular runout, after finishing hole location to install on the taper spindle, the axis of the hole for the locating datum A. Locating datum benchmark can be divided into coarse and fine benchmark. Surface used as positioning reference, if there is no the blank surface after machining, known as crude benchmark; If it is after cutting surface, it is called a fine benchmark.

②Measurement benchmark. Box pressure filter benchmark refers to the measurement of size and the surface of the machined surface is between the position precision of the datum, it is mainly used for inspection of parts.

③Process datum. Process benchmarking is used to determine the process of machining surface after the size, shape, position of the benchmark.

④Assembly benchmark. Press filter assembly benchmark refers to the assembly machine is used to determine the parts or components in the machine right benchmark.