Chapter VI. Sampling and Flow Measurement of Industrial Water and Industrial Waste Water

Abstract

A satisfactory sample of industrial water or waste water must meet two basic requirements: it must accurately represent the large or small mass sampled and it must be of adequate size for subsequent laboratory examination. Since industrial water and waste water must be sampled under a great variety of conditions, there is no single method that can be universally applied. The method, location, and time of sampling must be coordinated so the results obtained will serve the purpose for which the sample is intended. Industrial waters or waste waters are not fixed in their compositions but show appreciable changes depending upon their sources, seasonal precipitation, temperatures, pollutional wastes, and industrial processes. This chapter discusses variations in composition of industrial water and waste water related to environment and the mechanics of the sampling operation. These should serve as guides in determining the frequency of sampling, the appropriate points, and suitable sampling apparatus. In the study of industrial water as an engineering material, and in the handling, treatment, and disposal of industrial waste water, flow measurement is an essential function demanding applications of many types of flow-measuring devices and equipment to suit specific conditions. A brief summary of the classes and categories of flow-measuring devices, fundamentals of flow measurement, and description of flow devices and the important points to consider in their selection is included as part of this chapter.