A method for determining a carbon content value of a hydrocarbon-containing mixture. Here, the unexposed region information defines regions on the recording medium surface which are unexposed or cut away after printing and processing. Chamfering of a periphery of a GaN wafer is difficult. Eliminating such bridges eliminates the resulting grooves associated with previous arrangements. The first pivot part has a first end pivoted on the body and a second end connected to the first block part.