Daily consumption of gaseous chlorine may be checked by:

The correct answer focuses on the use of a platform scale to measure the daily consumption of gaseous chlorine. This method allows for the precise measurement of the weight of the chlorine cylinders before and after a given period, giving an accurate account of the amount consumed. Tracking the weight of the chlorine provides a clear and quantifiable way to monitor usage, which is essential for ensuring that the right dosage is being met for water treatment processes.

Using a scale, operators can easily determine the amount of chlorine remaining in the cylinder and calculate how much has been used over a specific time frame. This is particularly important in water treatment facilities to maintain safety and efficiency, as well as to adhere to regulations regarding chlorine usage.

In contrast, while chlorine demand, pressure reducers, and chlorine residual monitoring are important aspects of managing chlorination processes, they do not provide a direct measurement of the actual volume or weight of chlorine gas consumed. Chlorine demand measures how much chlorine is needed to achieve desired levels, pressure reducers help maintain consistent pressure in delivery systems, and chlorine residual testing indicates how much unreacted chlorine remains in the water. None of these methods measure the actual usage in the same direct way that a platform scale does.