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We've recently experienced excessive corrosion on stainless steel within indoor pool environments. We believe this is due to chloramine (gasses) in the atmosphere. To test this, I plan to create a small, closed environment (loosely sealed to contain gas but limit pressure buildup), in which I'll mix a solution to create some chloramines and hang material samples.

I assume (not from chemical background) that introducing pool chlorine (granular calcium hypochlorite 70%) and ammonia (as cloudy ammonia NH3 20g/L) to water, will kick most of this off. Attempts to maximise chloramines (Fig.1) will hopefully be achieved by keeping chlorine levels below breakpoint (Red local minimum - Fig.2)

Figure 1 - Choramines

Breakpoint Chlorination

I am slightly concerned after reading some articles and forums stating nitrogen trichloride (trichloramine) can be explosive. This factsheet states its only formed 'after breakpoint'. Additionally, some say 'in sunlight, will decompose', whilst others show it exploding in sunlight

Can anyone provide advice on how to safety generate monochloramine and dichloramine gasses without generating dangerous amounts of nitrogen trichloride?

I have an (ancient) Palintest photometer to monitor free/total chlorine but does not display ammonia.

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    $\begingroup$ At low pH values, nitrogen trichloride dominates and at pH 3–5 dichloramine dominates. These equilibria are disturbed by the irreversible decomposition of both compounds $\endgroup$
    – Nilay Ghosh
    Commented Sep 27, 2023 at 6:50
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    $\begingroup$ A dilute solution is irritating not explosive. But don't try to concentrate it or extract it. $\endgroup$
    – matt_black
    Commented Sep 27, 2023 at 19:28
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    $\begingroup$ For starters it's a Q&A site, not a forum... While pure NCl3 is explosive (kinda surprisingly) its dilute solutions aren't. I still don't get what you're trying to achieve there, and the post requires some copyediting. $\endgroup$
    – Mithoron
    Commented Sep 28, 2023 at 13:05
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    $\begingroup$ @Kuhrta if you want to know what not to do you should watch this $\endgroup$
    – matt_black
    Commented Sep 28, 2023 at 13:28
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    $\begingroup$ Why chances of "boom" would be really small, all these compounds are dangerous. I wouldn't try such experiment. Better analyse water (or air), check quality of steel and compare with data that are already available. $\endgroup$
    – Mithoron
    Commented Oct 2, 2023 at 12:20

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