The rotometer tube of a gas chlorinator indicates what measurement?

The rotometer tube of a gas chlorinator is used specifically to measure the flow of chlorine gas being fed into a water system. It is designed to provide a visual representation of the flow rate, typically in units like pounds per hour or pounds per 24 hours, which allows operators to manage the dosage of chlorine accurately. This is crucial for maintaining the desired levels of chlorine in the water for disinfection purposes.

This means that the rotometer directly indicates how much chlorine is being introduced over a specific time period, which is essential for achieving the correct chlorine concentration in the treated water. Monitoring this measurement helps ensure effective chlorination while preventing issues from under or over-dosing chlorine.

The other choices relate to different aspects of water treatment processes, but they do not pertain to the specific function of the rotometer in measuring the flow of chlorine gas. For instance, while chlorine concentration is important for water treatment, it is derived from the flow rate measurement indicated by the rotometer rather than being directly measured by it.