Product Code:SAE J1787
Title:Measurement of the Total Ash Content of Aviation Piston Engine Oils by a Calculation Method
Issuing Committee:E-38, Aviation Piston Engine Fuels And Lubricants
Scope:This SAE Recommended Practice describes an empirical method for determining the theoretical ash content of aviation piston engine lubricating oils by calculating the equivalent weight of metallic oxides formed at 775 掳C based on the metallic elemental concentration.The calculation method of ash determination may be used as an alternate to ASTM D 482 for application to the standards for aviation piston engine lubricating oils.Field of ApplicationThis procedure is recommended for use in the qualification, manufacturing, and quality assurance testing of aviation piston engine lubricating oils where the ash content is limited to a maximum of 0.011%.BackgroundThe ash content as measured by ASTM D 482 has very poor precision and repeatability for lubricants having low ash content. The precision statement for the method states that the reproducibility of a sample in the range of 0.001 to 0.079% ash content is 0.005%. Further, the bias of the test cannot be determined and there is no standard reference material containing a known level of ash for this method. This poor precision has led to numerous problems concerning the actual ash content of products on many occasions. The test method is valuable when run by experienced operators, but can provide dubious information if run under the general conditions stated in the method. For example, to obtain repeatable results, a platinum crucible must always be used in place of the silica or porcelain crucibles listed as equivalent substitutes. Meticulous care and procedural knowledge must be used by experienced operators for the method to be productive.The notes provided in ASTM D 482 also suggest that this method may not be appropriate for oils containing ashless additives or for oils containing certain phosphorous compounds which may now be in use in aviation lubricants. For oils containing additives an alternate method, ASTM D 874, is suggested. However, ASTM D 874 includes additional restrictions and reservattions which question the suitability of that method as an acceptable alternate or replacement for ASTM D 482 for low ash containing lubricating oils.【英文标准名称】:MEDICO-SURGICALEQUIPMENT.MATERIALSFORANCILLARYPOSITONINGINSTRUMENTSFORBONESURGERY.MARTENSITICANDAUSTENITICSTAINLESSSTEEL.
【原文标准名称】:外科医疗器械.骨外科安置用双刃器械的材料.马氏体和奥氏体不锈钢
【标准号】:NFS90-434-1990
【标准状态】:作废
【国别】:法国
【发布日期】:1990-12
【实施或试行日期】:1990-11-20
【发布单位】:法国标准化协会(AFNOR)
【起草单位】:
【标准类型】:()
【标准水平】:()
【中文主题词】:仪器;马氏体钢;耐腐蚀性;奥氏体钢;医疗设备;外科设备;质量等级;等级(质量);不锈钢;材料的机械性能;化学成份;机械性能
【英文主题词】:
【摘要】:
【中国标准分类号】:C35
【国际标准分类号】:
【页数】:10P;A4
【正文语种】:其他