Accurate measurement of water flow rates in large diameter pipelines is a challenge for water companies that need to produce, transport and distribute increasing quantities of water. To a large extent, this challenge results from the impossibility of recalibration of the flow meters within the periodicity established in the metrological regulations since the removal of a large size flow meter from its site of operation in the field and its transport to a calibration laboratory is in most cases technically and economically impracticable. Because of this scenario, this paper presents the pitometry technique as an interesting alternative to solve problems related to the validation of water flow measurements performed by flow measurement systems installed in large diameter conduits. The technique is based on the determination of the water flow rate by mapping the velocity profile of the water flow inside the pipe by means of Cole type Pitot tubes. The water flow rate is determined in a cross section of the pipe located near and in series to the flowmeter to be evaluated. Based on the results obtained in a great number of water flow measurements already performed by applying the pitometry technique in large diameter pipelines in the field, it is possible to conclude that this methodology is perfectly applicable in the validation of the performance of flow meters installed in these conduits solving satisfactorily the issues related to its operation.

对于需要生产，运输和分配越来越多的水的自来水公司，准确测量大直径管道中的水流量是一个挑战。在很大程度上，这一挑战是由于无法在计量法规规定的周期内重新校准流量计而造成的，因为从现场操作场所中取出大型流量计并将其运输到校准实验室非常困难。在大多数情况下，从技术上和经济上都不可行。由于这种情况，本文提出了一种测深技术，作为解决与安装在大直径管道中的流量测量系统进行的水流量测量验证相关的有趣替代方法。该技术基于通过使用Cole型皮托管来绘制管内水流的速度分布图来确定水流率的方法。在与待评估流量计相邻并串联的管道横截面中确定水流量。根据在野外大口径管道中通过应用测井技术已经进行的大量水流量测量获得的结果，可以得出结论，该方法非常适用于验证安装在水表中的流量计的性能这些管道令人满意地解决了与其运行有关的问题。在与待评估流量计相邻并串联的管道横截面中确定水流量。根据在野外大口径管道中通过应用测井技术已经进行的大量水流量测量获得的结果，可以得出结论，该方法非常适用于验证安装在水表中的流量计的性能这些管道令人满意地解决了与其运行有关的问题。在与待评估流量计相邻并串联的管道横截面中确定水流量。根据在野外大口径管道中通过应用测井技术已经进行的大量水流量测量获得的结果，可以得出结论，该方法非常适用于验证安装在水表中的流量计的性能这些管道令人满意地解决了与其运行有关的问题。