There is density maintenance of the chlorine which remains behind to maintain it of hygiene of the water in a bathhouse institution. It is the present conditions now to measure by DPD method and SBT method as simple measurement. However, there is FACTS method in standard methods(america). I intended to introduce this method into measurement of our country. I examined precision of FSCTS method in comparison with DPD method and SBT method. As a result, I got equal evaluation.
