本文件规定了使用消光技术（也称为光阻挡或光遮蔽）在线或离线测定容器中颗粒污染水平的方法。它还定义了在实验室和使用中校准仪器和验证其正确运行的程序。 一般来说，本文件中描述的技术适用于监测: -液压系统的一般清洁度水平， -冲洗作业的进展，以及 -支持设备和试验台。 该方法仅适用于单相液体系统。

This document specifies a method for the determination of the particulate contamination level using the light extinction technique (also known as light blockage or light obscuration) either online or offline in containers. It also defines procedures for calibrating the instruments and verifying their correct operation both in the laboratory and in service. In general, the techniques described in this document are suitable for monitoring: — the general cleanliness level in hydraulic systems, — the progress in flushing operations, and — support equipment and test rigs. The use of this method is applicable to single-phase liquid systems only.