LUBRICATING OIL COMPOSITION AND METHOD FOR MANAGING PRODUCTION LINE

摘要

This method for managing a production line is provided with: a step of preparing a lubricating oil composition which comprises, based on the total amount of the lubricating oil composition, 50 mass% or more of a base oil in which the aniline point and kinematic viscosity at 40°C satisfy the condition represented by formula (1): 0.4×(aniline point)-15×log(kinematic viscosity at 40°C)≥20 (1) and which does not emit visible light when irradiated with ultraviolet light by a black light; and in a production line in which a lubricating oil is used, a step of using the lubricating oil composition and monitoring contamination, fouling or degradation of a product due to substances that are luminescent under ultraviolet light by irradiating the product with ultraviolet light.