This instrument is specialized for test the content of Sulphuric Acid in the chrome plating solution, this method is simple and convenient, fast, with little error. The test result can be got within 10 minutes. There is no need to make working curve (direct reading and getting result). It is not necessary to confect standard solution, what's more, two samples can be analysed one time. This instrument solves the shortage of titration complexometric titration and weight method (complexity, long time, may cause error), and it is good underservant in the process of chrome plating solution analysis.