한국주조공학회

The effects of various factors on the measurement error during the measurement of hydrogen concentration in A356 Al alloy melt were investigated. The error value of the calculation of hydrogen concentration had about 0.0028 ml H21100g Al. Effects of suspended weight and wetted weight measurement was large in use of a weighing beam. But the error of suspended weight was largest in dried and suspend weight measurements in the consideration of environmental problems because it had both effects of used wire and temperature measurement error. As the weight of test casting increased and the test absolute pressure decreased, the error of hydrogen concentration measurement decreased. Also, in suspended weight, the different volume of used water in the measurement of suspended weight gave the big error in hydrogen concentration measurement and the heavier samples had little affected by this effect. So relative constant sample weight with above 100 g, well-known constant water temperature and volume in the measurement of suspended weight were required to get the possible exact value of hydrogen concentration.