Abstract: An analog-digital converting unit converts the electrical quantity obtained from a power system into a digital amount. A non-volatile memory stores a protective control program that achieves the function of a digital protective control device. A processor executes the protective control program to perform arithmetic processing on the digital amount output by the analog-digital converting unit. The protective control program includes a basic program and an added program divided in accordance with the function of the digital protective control device. The added program includes valid operation period information. The processor executes the added program within the valid operation period.

Abstract: To provide a material for devices that require good corrosion resistance and a property of less liquid remaining, such as jigs to load an article to be treated in a wet process and spray chambers for ICP analysis. At least the surface of the devices that require good corrosion resistance and a property of no liquid remaining on the surface comprises glassy carbon with a surface roughness (Ra) of 10 ?m or less. When the device is a jig to load an article to be treated in a wet process, the purity of the surface to be in contact with liquid is 50 ppm or less in terms of ash content and the surface roughness (Ra) is 0.1 ?m or less. When the device is a spray chamber for ICP analysis, Ra is 0.1-10 ?m and the purity of the surface to be in contact with liquid is 50 ppm or less.

Abstract: The glassy carbon according to the present invention is obtained by heat-curing a phenolic resin and firing the cured-phenolic resin in a non-oxidizing atmosphere, wherein the phenolic resin has a number-average molecular weight of 300-500 and is used in the form of a hydrophilic organic solvent solution containing 40-80% by weight of the phenolic resin; and the process comprises heat-curing a phenolic resin and firing the cured-phenolic resin in a non-oxidizing atmosphere, wherein the phenolic resin has a number-average molecular weight of 300-500 and is used in the form of a hydrophilic organic solvent solution containing 40-80% by weight of the phenolic resin.

Abstract: The present invention provides an instrument for production of a semiconductor device, which consists essentially of a vitreous carbon derived from a polycarbodiimide resin, and a process for producing an instrument for production of a semiconductor device, which comprises molding a polycarbodiimide resin or a composition composed mainly of a polycarbodiimide resin, into a shape of an instrument for production of a semiconductor device and then carbonizing the molded material in vacuum or an inert gas atmosphere. Said instrument for production of a semiconductor device is free from the problems of conventional instruments and can be produced easily at a high purity and at a low cost.

Abstract: A substrate for magnetic recording medium, consisting essentially of a vitreous carbon produced from a polycarbodiimide resin; and a process for producing a substrate for magnetic recording medium, which comprise molding into an appropriate shape a polycarbodiimide resin or a composition mainly comprising a polycarbodiimide resin, carbonizing the shaped material, and processing the carbonized shaped material into a substrate for magnetic recording medium.Said substrate for magnetic recording medium is free from the problems of the prior art, is lightweight and thin, has excellent mechanical strengths and a smooth and dense surface having substantially no pore, and can be produced at a low cost.

Abstract: An electrode plate for use in plasma etching, which includes a vitreous carbon material produced from a polycarbodiimide resin as a raw material, or from a phenolic resin and a polycarbodiimide resin each as a raw material.The vitreous carbon material produced from a polycarbodiimide resin or from a phenolic resin and a polycarbodiimide resin, has no or substantially no pores and has a high strength. Therefore, it exhibits excellent properties when used in an electrode plate for plasma etching.

Abstract: A carbon target material for forming a carbon thin film, includes a vitreous carbon produced from a polycarbodiimide resin. A process for producing a carbon target material for forming a carbon thin film includes molding into an appropriate shape a polycarbodiimide or a composition primarily composed of a polycarbodiimide and then carbonizing the resulting shaped material.The carbon target material for forming a carbon thin film; causes no abnormal discharge during sputtering generates no powder leading to contamination during sputtering, and has high purity.

Abstract: A process for producing a substrate for magnetic recording medium, which includes molding into an appropriate shape a polycarbodiimide resin or a composition mainly containing a polycarbodiimide resin, carbonizing the shaped material, and processing the carbonized shaped material into a substrate for magnetic recording medium.

Abstract: A suscepter, which is composed substantially of a vitreous carbon derived from polycarbodiimide resin; and a process for producing a suscepter, which includes molding a polycarbodiimide resin or a composition composed mainly of a polycarbodiimide resin, into a shape of a suscepter and then carbonizing the molded material in vacuum or an inert gas atmosphere.The suscepter is free from the problems of the prior art, which has no pores on the surface and generates no impurity and which causes no cracking when used at high temperatures.