Pinhole and micro-shrinkage are the ordinary defects founded in the aluminum and magnesium alloy castings,the existence of hydrogen is the main reason for these defaults. So the measurement of hydrogen in aluminum and magnesium alloy melt is an important means to test the degassing effect and to ensure the quality of the melt,and it is significant to improve the casting's quality.With the increasing application of aluminum and magnesium alloy,the development of quantitative and rapid measurement of hydrogen...