MQ 135 Ammonia sensing characteristics

Hai guys,
I recently bought an mq 135 gas sensor for detecting ammonia using arduino,even though the datasheet says it can detect ammonia,the sensing characteristics graph gives the following labels…can someone tell me which shows ammonia…

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NH3 is ammonia, I assume that the NH4 in the graph is the ammonia. For the other gasses, find someone who speaks Chinese and look into an original chinese datasheet for the MQ135. According to Google Translate there are 3 totally different ways in chinese to write "ammonia".

Has there never been someone who has translated the MQ135 datasheet into English, including the names of the gasses in the graph ? It is too silly to be true, but no one has done that.

Adsorbed NH3 may well be in the form of NH4, that extra bond is how it gets adsorbed? Anyway it could be a misprint, but HN3 or HN4 can be taken to be the species of interest, just as water molecules rapidly switch between OH-, H2O and H3O+

Don't ask me why water is H2O and ammonia is NH3 rather than H3N (!) Modern chemists are using OH2 these days I believe.