自从《地表水处理规则》（SWTR）颁布并确认隐孢子虫病和贾第虫病暴发以来，人们对颗粒计数器作为水处理设施的过程监测设备的兴趣有所增加。本文分析了水处理设施中使用的颗粒计数方法，将带有前向角光散射（FALS）传感器的颗粒计数器计数与扫描电子显微镜和显微镜颗粒分析计数进行比较。一项单独的研究比较了FALS传感器与光遮蔽传感器在乳胶球和培养微生物的激发下以及在连续光照条件下的表现- 设施过滤废水的管线计数。在颗粒计数方法中，对数去除值具有可比性，并且在FALS传感器的不同尺寸范围内没有显著差异。与光学显微镜测定的尺寸相比，这两种传感器类型的微生物尺寸都较小。这些结果表明计数器准确地指示了设施颗粒去除效率。然而，在描述源中粒子的性质后，应解释特定尺寸范围内粒子计数器的计数。包括22个参考文献、表格和图表。

Since promulgation of the Surface Water Treatment Rule (SWTR) and confirmed outbreaks of cryptosporidiosis and giardiasis, interest in particle counters as a process monitoring device for water treatment facilities has increased. In this article, particle counting methods for use in a water treatment facility were analyzed to compare counts made by a particle counter with a forward-angle light scatter (FALS) sensor with counts made with a scanning electron microscope and by microscopic particulate analysis. A separate study compared a FALS sensor with a light obscuration sensor when challenged with latex spheres and cultured microorganisms and when performing continuous in-line counts of the facility's filter effluent. Log removal values were comparable among the particle counting methods and did not vary significantly across various size ranges of a FALS sensor. Microorganisms were undersized by both sensor types compared with sizes determined with an optical microscope. These results suggest counters accurately indicate facility particle removal efficiency. However, counts made by a particle counter within a specific size range should be interpreted after characterizing the nature of the particles in the source. Includes 22 references, tables, figures.