To determine the concentration of the analyte, these kits utilize a titration technique which consists of counting the number of drops of titrant necessary to cause a color change in the sample.

• 比色测定组的特点有：反应容器上具通口护盖，避免样品溶液溢洒出来；可精确计算滴数的滴瓶、绢印似的塑反应容器和事先已标定的试剂。