Question

How does a soap-bubble flow meter work?

Short answer

A soap bubble flow meter is used to determine the rate of flow of a gas.

Step-by-step solution

Introduction

A soap bubble flow meter is used to determine the rate of flow of a carrier gas. The instrument has a glass tube with a measuring scale, rubber caps, and a right-angled tube connected with nose connectors and attached to the column. It consists of a rubber bulb at the end to carry the aqueous solution of soap or detergent.

Working Principle

In order to take measurements, the user squeezes the rubber bulb at the end. As the soapy water goes above the sidearm, a film of soap water is formed in the path of the gas. The time required by the soap solution to move across the two points is noted and the volumetric flow rate is evaluated accordingly.