1.1本规程涵盖校准和确定光学液载粒子计数器（LPC）性能的程序，该计数器使用基于消光测量的光学系统。本规程旨在确定LPC的精度和分辨率，以表征已进入LPC样品入口的颗粒的大小和数量。考虑入口采样效率不是本实践的一部分。 1.2本规程涵盖的程序包括测量样品体积和流速、零计数水平、粒度和计数精度、粒度分辨率、颗粒计数效率和颗粒浓度极限的程序。 1.3本规程中报告的粒径参数是基于分散在液体中具有已知物理性质的校准颗粒投影面积的等效光学直径。制造商通常指定LPC可以报告的最小直径；所用LPC的动态范围决定了单个样本可以报告的最大直径。典型的最小报告直径约为2´m，典型的动态范围规格约为50到1。 1.4 LPC的计数率能力受到LPC传感体积中粒子的时间一致性以及电子尺寸和计数电路的饱和水平或最大计数率能力的限制。 重合被定义为在任何时间LPC光学定义的传感区内同时存在一个以上的粒子。当颗粒尺寸与传感体积尺寸相比微不足道时，重合极限是样品中颗粒浓度和传感区体积的统计函数。这种限制可能会因存在尺寸大到相当于传感区尺寸的颗粒而改变。电子计数电路的饱和水平率应由制造商规定，并且通常大于LPC建议的用于本实施规程任何部分的颗粒浓度的最大计数率。 1.5 LPC的常规现场校准可能不需要按照本规程的所有部分进行校准，除非LPC的操作发生了重大变化，或进行了主要部件的维修或更换。然后，应将LPC带到适当的计量设施进行完整校准。常规现场校准可确定样品流速、零计数水平和粒度精度。待校准的特定LPC功能应根据买方和用户之间的协议确定。校准之间的最大时间间隔应由买方和用户之间的协议确定，但不得超过12个月，除非根据本惯例通过测量验证LPC更长时间的稳定性。 1.6 本标准可能涉及危险材料、操作和设备。本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全和健康实践，并确定监管限制的适用性。

1.1 This practice covers procedures for calibrating and determining performance of an optical liquid-borne particle counter (LPC) which uses an optical system based upon light extinction measurement. This practice is directed towards determination of accuracy and resolution of the LPC for characterizing the size and number of particles, which have been passed into the sample inlet of the LPC. Consideration of inlet sampling efficiency is not part of this practice. 1.2 The procedures covered in this practice include those to measure sample volume and flow rate, zero count level, particle sizing and counting accuracy, particle sizing resolution, particle counting efficiency, and particle concentration limit. 1.3 The particle size parameter reported in this practice is the equivalent optical diameter based on projected area of calibration particles with known physical properties dispersed in liquid. The manufacturer normally specifies the minimum diameter that can be reported by an LPC; the dynamic range of the LPC being used determines the maximum diameter that can be reported for a single sample. Typical minimum reported diameters are approximately 2 ´m, and a typical dynamic range specification will be approximately from 50 to 1. 1.4 The counting rate capability of the LPC is limited by temporal coincidence of particles in the sensing volume of the LPC and by the saturation level or maximum counting rate capability of the electronic sizing and counting circuitry. Coincidence is defined as the simultaneous presence of more than one particle within the LPC optically defined sensing zone at any time. The coincidence limit is a statistical function of particle concentration in the sample and the sensing zone volume when particle size is insignificant in comparison to the sensing volume dimensions. This limitation may be modified by the presence of particles with dimension so large as to be a significant fraction of the sensing zone dimension. The saturation level rate of the electronic counting circuitry shall be specified by the manufacturer and is normally greater than the LPC recommended maximum counting rate for the particle concentrations used for any portion of this practice. 1.5 Calibration in accordance with all parts of this practice may not be required for routine field calibration of an LPC unless significant changes have occurred in operation of the LPC or major component repairs or replacements have been made. The LPC shall then be taken to a suitable metrology facility for complete calibration. Normal routine field calibration may determine sample flow rate, zero count level, and particle sizing accuracy. The specific LPC functions to be calibrated shall be determined on the basis of agreement between the purchaser and the user. The maximum time interval between calibrations shall be determined by agreement between the purchaser and the user, but shall not exceed twelve months, unless LPC stability for longer periods is verified by measurements in accordance with this practice. 1.6 This standard may involve hazardous materials, operation, and equipment. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.