The only way to achieve a specified purity level is to select and install proper filtration for the job intended and the task fully understood. Norman Hall, Filtration Business Unit manager for Valin Corporation, suggests a correct approach.

中文翻译：

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了解原料

达到指定纯度的唯一方法是为预期的工作和充分理解的任务选择并安装适当的过滤器。Valin Corporation过滤业务部门经理Norman Hall提出了正确的方法。