In or der t o assur e that the low pr essur e bo iler tot al feedw ater har dness does no t sur pass 0. 03mm ol/ L, a co rr espo nding a nalysis metho d is used accor ding to the situatio ns. The operat ing terminal o f ion ex change container is contr olled. Aft er the pr omo tio n or o peration per so nel tr aining , t he metho d is used ex tensively and go od societ y efficiency has been obtained.