铝合金、水
电子秤
营口象圆选择预热坩埚，接通系统电源。Preheat crucible and switch on system power.设定抽真空时间为120～150秒之间。Set vacuumizing time: between 120-150 seconds. 待测铝液准备好以后，把预热好的坩埚放在浇注平台上。After preparing aluminum liquid which is to be tested, put the preheated crucible on the pouring platform. 浇注试样，盖上钟罩，同时打开真空泵抽真空，真空表的指示应为-0.093～-0.098Mpa之间。Pouring test sample, cover bell jar, turn on vacuum pump and start vacuumizing, the indicator of vacuum meter should be between -0.093～-0.098Mpa.到设定时间，真空泵自动关闭，系统自动吸压
待试样凝固后，取下钟罩，取下坩埚，取出试样，准备称重。After solidification of test sample, take down bell jar and crucible, take out test sample, prepare to weight.称重时，先把试样在电子称上方称量在空气中质量（W1）再把试样放在电子拖拉下方水槽中（保证试样全部浸入水中）称量在水中质量（W2）When weighting, firstly, weigh the test sample on the electronic scale and get the mass of test sample in the air. Then put the test sample in the water basin which is under the electronic drag (ensure the whole test sample has been into the water) and get the mass of test sample in the water.
计算 铝合金密度： ρ= W1/W1-W2 （g/cm3）Calculating density of aluminum alloy:试中：W1——试样在空气中质量W2——试样在水中质量
.减压凝固试样密度与常压试样针孔度等级的对应关系（试验值）。判定Corresponding relationship between pressure reducing and solidified test sample and pin hole grade of test sample under normal pressure.(test value)判定：针孔度等级，二级以内为合格
检查钟罩底部及上部密封圈，并空载测试系统真空度
试样称重时，把测量架放在水槽中后，电子秤的指示必须为零
试样称量水中重量时，试样要全部浸入水中