Question 1012 of 229 · California Water Distribution Operator Exam
Which test is most often used by operators in the field to measure chlorine residual?
Exactly one answer is correct.
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Correct answer to question 1012
- A: DPD colorimetric test
Explanation
DPD reagent turns pink in proportion to chlorine, and a colorimeter or comparator reads the result. The jar test, Langelier index and membrane filter test serve other purposes.
More questions: Disinfection
- 1013A sudden drop of chlorine residual at a dead-end hydrant most likely points to what?
- 1014Before a newly disinfected main is placed in service, what must the bacteriological samples show?
- 1015Which standard covers the disinfection of new and repaired water mains?
- 1016A well is most likely to need disinfection in which situation?
- 1017Which of the following is a common source of contamination of a water storage reservoir?
- 1018Chlorine gas is heavier than air. Where should an operator expect leaking gas to collect?