Which test is used to measure the presence of chloramines in pool water?

The combined chlorine test is specifically designed to measure the presence of chloramines in pool water. Chloramines are formed when free chlorine combines with ammonia and organic nitrogen compounds in the water, typically from swimmer waste and other contaminants.

In this context, the combined chlorine test differentiates between free chlorine and combined chlorine (which includes chloramines). By measuring the total chlorine present and subtracting the free chlorine level, one can determine the amount of combined chlorine, which indicates the presence of chloramines. High levels of chloramines are undesirable as they can cause irritation to the eyes and skin of swimmers, as well as lead to unpleasant odors.

In contrast, the other testing methods focus on different aspects: the pH test assesses the acidity or alkalinity of the water, the free chlorine test measures the amount of chlorine available to actively sanitize the water, and the total dissolved solids test evaluates the concentration of dissolved substances in water, but none of these tests specifically assess chloramine levels. Thus, the combined chlorine test is the appropriate choice for this particular measurement.