Ontario Operator-in-Training (OIT) Practice Exam 2025 - Free OIT Practice Questions and Study Guide

Measuring flow in a closed pipe is crucial for various applications, including water treatment and distribution systems. Venturi meters and ultrasonic meters are specifically designed for this purpose and are widely used due to their efficiency and accuracy.

Venturi meters operate based on the principle of fluid dynamics. As fluid flows through a constricted section of the pipe, the velocity of the fluid increases, leading to a decrease in pressure. By measuring the pressure differential between the wider and narrower sections of the pipe, the flow rate can be calculated accurately. This makes Venturi meters ideal for applications where precise flow measurement is required.

Ultrasonic meters use sound waves to determine the flow rate. By sending ultrasonic signals through the fluid and measuring the time it takes for the signals to travel upstream and downstream, these meters can calculate the flow velocity. This non-invasive method is advantageous for many applications, as it does not disrupt the flow and can be installed without cutting into the pipe.

Other choices, such as flow gauges, weight measurements, and pressure differential gauges, do not specifically address all the aspects of flow measurement as effectively as Venturi and ultrasonic meters. Therefore, the selection of Venturi meters and ultrasonic meters aligns perfectly with the requirements for measuring flow in a closed piping system.