An autonomic nervous activity monitor capable of predicting occurrence of abnormal reaction depending on autonomic nervous activity and used for medical practice and the like is provided. The barcode is printed directly on an outer peripheral surface of a barrel of a test tube body by an inkjet printer. Sub-bands of the channels are processed individually, and a measure of the power of each sub-band is used to determine a coupling coefficient generation scheme for each individual sub-band. With this arrangement, the amount of generated light carriers can be reduced on the axially central part, as compared with the axially opposite ends, and a surface potential distribution non-uniformity due to a difference in nip distance between the photosensitive drum and a charging roller can be eliminated. This fluid is oil-wetting to solids, and in general behaves like a traditional oil mud. 5% by mass and not more than 10% by mass based on the total mass of whole resin in the charge transporting layer.