an immersion liquid saturated with the soluble components of
the sample shall be ud.
8.Standardization of Pycnometer
高中入团申请书
8.1Fill the pycnometer with freshly boiled distilled water at
23to 24°C;gradually bring to 2560.5°C in the water bath,
and then remove,dry,and weigh it as described in 9.1.Empty
陈粒歌曲the pycnometer,then clean,dry,and reweigh it.Next,fill the
pycnometer with the immersion liquid at 24°C or less,and
bring to 2560.5°C in the water bath.Remove from the bath,
dry,and weigh as before.Calculate the density of the
immersion liquid as follows:
D ensity at 25°C ,M g/m 35~A /B !30.997(1)where:A 5mass of immersion liquid,and B 5mass of water,0.9975density of water at 25°C,Mg/m 3.
9.Procedure
番茄花9.1Weighing —Transfer a sufficient amount of the test
specimen to a clean,dry,weighed pycnometer to form a layer
垃圾分类活动总结approximately 19mm (3⁄4in.)deep and reweigh.Weigh rubber
chemicals of a hygroscopic nature from a weighing bottle.
9.2Addition of Immersion Liquid —Add sufficient
immersion liquid to the pycnometer to form a thin layer above
the rubber chemical.When necessary,swirl the contents of the
pycnometer by hand,to wet the sample.
9.3Removal of Occluded Air —Place the pycnometer in the
desiccator,clo,and attach to the pump for the removal of air.
Take care not to decrea the pressure too quickly,otherwi
some of the sample may be lost due to the sudden removal of
the entrapped air.A pinch-cock may be ud to control the rate
of evacuation.The pressure meter is ud to indicate whether
the oil pump is giving the proper vacuum,which is an absolute
pressure of 0.2kPa.Bubbles of air ri from the sample rapidly
at first,then decrea and finally stop.The time required for浙贝母的功效与作用
complete removal of air may vary from 30min to 24h.When
no more bubbles can be en,it may be assumed that occluded
安在模air has been removed and the rubber chemical is thoroughly
四年级下册人教版
wet with immersion liquid.Slowly readmit air to the迎亚运
desiccator.
N OTE 2—If an immersion liquid is ud who vapor pressure is greater
than 0.2kPa at room temperature,the liquid will evaporate,often with“
bumping.”Therefore it is necessary to adjust the vacuum to a higher
pressure with some loss in effectiveness of air removal.The u of such
immersion liquids should be limited to tho cas in which no low vapor pressure liquid can be u
d.In no ca should a mixed liquid be ud in which any component has an appreciable vapor pressure.
9.4Final Adjustment —Remove the pycnometer from the desiccator,fill with immersion liquid at 24°C or less,taking care to add a sufficient quantity to prevent air bubbles remaining in the pycnometer when clod.Inrt the stopper,being careful not to trap any air bubbles.Place the pycnometer in the water bath and permit it to come to constant temperature at 2560.5°C.Remove from the water bath,wipe the end of the capillary with lint-free toweling or lens paper,making sure not to suck any liquid from the capillary.Cap the capillary.Dip the pycnometer (up to the side arm)in a beaker of alcohol to remove any residual immersion liquid.Thoroughly dry the outside of the pycnometer and weigh.9.5Number of Specimens —Make duplicate tests on all specimens.10.Calculation 10.1Calculate the density of the rubber chemical as follows:D ensity at 25°C ,M g/m 35PS /@~P 1K !2F #(2)where:P 5mass of rubber chemical ud,S 5density of the immersion liquid,K 5mass of the pycnometer filled with immersion liquid,and F 5final mass of the pycnometer with rubber chemical and immersion liquid.11.Report 11.1Report the following information:11.1.1Name of the rubber chemical,11.1.2Density at 25°C,Mg/m 3,and 11.1.3Immersion liquid ud.12.Precision and Bias 12.1Precision —This test method has not been tested for reproducibility or repeatability,but duplicate
determinations on the same sample should not differ by more than 0.02Mg/m 3at 25°C.12.2Bias —No statement about bias is being made at this time.13.Keywords 13.1density;rubber chemicals
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asrted in connection with any item mentioned in this standard.Urs of this standard are expressly advid that determination of the validity of any such patent rights,and the risk of infringement of such rights,are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revid,either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standards and should be addresd to ASTM Headquarters.Your comments will receive careful consideration at a meeting of the responsible technical committee,which you may attend.If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards,100Barr Harbor Drive,West Conshohocken,PA
19428.
