Introduction:
The orifice meter is a type of flow meter used to measure the rate of flow of fluid through a pipe. It works based on the principle of fluid flow through a small opening, known as an orifice plate. However, the statement that orifice meters can only be used for measuring the rate of flow in an open pipe-like structure is incorrect.

Explanation:
1. What is an orifice meter?
An orifice meter consists of an orifice plate, which is a flat plate with a hole in the center, inserted into the pipe. As the fluid flows through the orifice, it creates a pressure drop across the plate, which is measured to determine the flow rate.

2. Usage of orifice meters:
Orifice meters are commonly used in various industries for measuring the flow rate of liquids, gases, and steam. They are suitable for both open and closed pipe systems, making them versatile flow measurement devices.

3. Open pipe systems:
In open pipe systems, the fluid flows freely without any confinement or pressure. Examples include rivers, canals, and open channels. Orifice meters can be used in open pipe systems to measure the flow rate by installing them across the channel or using a flume.

4. Closed pipe systems:
In closed pipe systems, the fluid is confined within pipes under pressure. These systems are commonly found in industrial processes and water supply networks. Orifice meters can also be used in closed pipe systems to measure the flow rate by installing them in the pipe.

5. Advantages of orifice meters:
- Simple and cost-effective design
- Wide range of applications
- Accurate and reliable flow measurement
- Low maintenance requirements

Conclusion:
In conclusion, the statement that orifice meters can only be used for measuring the rate of flow in an open pipe-like structure is false. Orifice meters can be used in both open and closed pipe systems to measure the flow rate of various fluids. Their versatility, accuracy, and cost-effectiveness make them a popular choice for flow measurement applications in different industries.