Dear Prof. Karaman

Thank you

Regard

I do not understand what you mean؟

Dear Rafik,

I suggest to do this a bit more relaxed. - by the by it was not me downvoting you ;-).

some people like answers others do not.- that can have different reasons. they found it easy to understand/difficult to understand, they found it helpfull for their work/not helpfull for their work, they might agree or disagree. I often downvoted discussions that were below textbook level, were I had the feeling I should just scream read just the beginners books and you would not ask such question - certainly not relevant here...

please look at this paper :

http://www.ozonesolutions.com/info/ozone-monitor-calibration

http://www.europeanpharmaceuticalreview.com/wp-content/uploads/White_Paper-Hach-Lange.pdf

also the time for ozonemeter calibration will be differ according to your application

kind regards,

Dear

Depending on the type of device calibration is different!