(It is not quite clear what exactly you want to do) If your application is drinking water, have a look at the WEDC website. I think they had a Technical Brief on exactly that explaining the Horrock's method. It essentially allows you to perform chlorine demand tests without knowing the exact hypochlorite solution concentration by using readily available materials on a volumetric basis.
Cheers,
Caetano

Sometimes I think we need a proper WASH message board again, as questions like this are quite far off the normal spectrum for SuSanA...

I assume the background of your question is preparing (medical) cleaning solutions from locally available bleach powder?

Putting "preparing bleach solution" into google gave me the attached document as the first hit.

Dear Team,

I am working in an organization related with WASH activities in Ethiopia. Now, I would like to request you that how can I prepare strong and weak chlorine solution in context where graduated recipients are not available? would you like to send me doc about preparation of chlorine solution in the context of emergency situation?

Sincerely,
Wubishet