The test items include:determination of particle size distribution of graphite electrode plate; Determination of solid composition; Determination of volatiles; Determination of pH value; Determination of grain size; Determination of film resistivity; Determination of adhesion; Determination of porosity; Determination of moisture resistance; Determination of iron and copper content, in addition can also determine the product's heat resistance and film lubrication, etc.

The particle size distribution of the graphite electrode plate is determined as follows: the particle size distribution of the graphite electrode plate particles below 1pm is determined by electron microscopy and gravity sedimentation. The advantage of electron microscopy is that it can not only determine particle size distribution, but also know the shape of particles. The frequency distribution of graphite particles is measured by 10,000 times electron micrography. The measuring device of gravity settling method is overspeed centrifuge. The overspeed centrifuge measures the particle size distribution of graphite plates at a force 10,000 times that of gravity (the maximum centrifugal force of a conventional laboratory centrifuge is 2,000 times that of gravity).

In current production practice, sedimentation method is used to determine the particle size of graphite particles larger than lHm. The powder sample was suspended and dispersed in pure water, and dispersant was added to prevent the particles from condensing. Then the graphite electrode plate was diluted to a thin slurry with a graphite concentration of 0.05%, and then loaded into a container, and the particle size was determined by gravity settling balance. Gravity settling balance is a kind of automatic particle size distribution measuring instrument with automatic recording device. This instrument can measure the grain size distribution curve of a sample.