# Notch is a device used for measuring

By BYJU'S Exam Prep

Updated on: September 25th, 2023

The rate of flow of a liquid through a tank or a small channel is measured by using a Notch device. It converts the pressure energy of liquid into kinetic energy. It is an opening in the side of the small channel such that the liquid surface in the small channel or tank is below the top edge of the opening.

## Answer: Notch is a device used for measuring the rate of flow of a liquid through a tank or a small channel.

It causes the water to rise behind it in order to make the water flow through it or over it. There is another device known as Weir which is used for measuring the flow of a liquid. The notch device is small in size whereas the size of the weir is large. Weir and Notch are made up of concrete and metal plates respectively.

### Classification of Notch

Notch is classified into three categories namely: Rectangular notch, Triangular notch, and Trapezoidal notch.

• Rectangular notch: It is a rectangular-shaped notch that is installed at the end of the upstream to offer more pressure drop. The rate of flow in this notch is dependent on the depth of the upstream.

• Triangular notch: It is also known as V-notch. It is helpful in measuring the low flow rate. In this notch, pressure loss can be recovered.

• Trapezoidal notch: It is a combination of a rectangular notch and two triangular notch. In this, the sum of discharge will be the sum of discharge of rectangular notch and triangular notch.

Summary:

## What does the Notch device measure?

A notch device is used for the measurement of the flow rate of a liquid through a small channel.