| 摘要 |
PURPOSE:To shorten time required to reach constant weight and make it possible to measure fast by using an aluminium cup that is reduced to constant weight by two-time operation consisting of drying at 110 deg.C for 1hr, cooling for 30min, drying at 80+ or -5 deg.C for 30min and cooling for 15min. CONSTITUTION:An aluminium cup is dried at 110 deg.C for one hour, cooled for 30min and it is weighed. Next it is dried at 80+ or -5 deg.C for 30min and cooled for 15min, and it iis weighed. Thus the cup goes through two-time operation to be reduced to a constant weight. Next, a specimen is put in this aluminium foil cup, and the cup is placed on a hot plate at 80 deg.C for about 1-2hr to make only n-hexan extracted. Then after the aluminium foil cup with the n-hexan in the specimen extracted is dried at 80+ or -5 deg.C for 30min and cooled for 15min, the weight of extracted n-hexan is measured by weighing the aluminium cup. In this way the constant weight process can be omitted and, further, if the aluminium cup is washed by a little amount of n-hexan, it can be used many times. |
