1.1 本试验方法包括使用玻璃比重计结合一系列计算对原油、石油产品或通常作为液体处理的石油和非石油产品混合物的密度、相对密度或API比重进行实验室测定，雷德蒸汽压为101.325 千帕（14.696 psi）或更小。值在现有温度下确定，并修正为15 °C或60 通过一系列计算和国际标准表。 1.2 获得的初始比重计读数是未经校正的比重计读数，而不是密度测量值。在参考温度或其他合适温度下，在比重计上测量读数，并通过石油测量表校正弯液面效应、热玻璃膨胀效应、替代校准温度效应和参考温度的读数； 在参考温度以外获得的值是比重计读数，而不是密度测量值。 1.3 通过相互转换程序（API 英里/分钟 第11.5章），或附属 第1250天 石油计量表指南（API 英里/分钟 第11.1）章，或两者，或表格，视情况而定。 1.4 在进行任何计算之前，应记录实验室中确定的初始比重计读数。第节中要求的计算 10 应适用于初始比重计读数，并按照第节的要求报告观测结果和结果 11 在随后的计算过程中使用之前（票据计算、流量计系数计算或基本校准体积确定）。 1.5 附件A1 包含验证或认证本试验方法设备的程序。 1.6 以国际单位制表示的值应视为标准值。 1.6.1 例外情况- 括号中给出的值仅供参考。 1.7 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前建立适当的安全和健康实践，并确定监管限制的适用性。 1.8 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《国际标准、指南和建议制定原则决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 5.1 在15℃的标准参考温度下，准确测定石油及其产品的密度、相对密度（比重）或API比重是将测量体积转换为体积或质量或两者的必要条件 °C或60 监护转移期间的温度为°F。 5.2 该程序最适用于测定低粘度透明液体的密度、相对密度（比重）或API比重。该程序也可用于粘性液体，通过允许液体比重计有足够的时间达到温度平衡，以及用于不透明液体，通过采用合适的弯月面校正。此外，对于透明和不透明流体，在校正至参考温度之前，应针对热玻璃膨胀效应和替代校准温度效应校正读数。 5.3 当与散装油测量一起使用时，通过在接近散装油温度的温度下观察比重计读数，可将体积校正误差降至最低。 5.4 密度、相对密度或API比重是决定原油质量和价格的因素。然而，除非与其他财产相关，否则石油的这种属性是其质量的不确定指标。 5.5 密度是汽车、航空和船用燃料的重要质量指标，它影响储存、处理和燃烧。

1.1 This test method covers the laboratory determination using a glass hydrometer in conjunction with a series of calculations, of the density, relative density, or API gravity of crude petroleum, petroleum products, or mixtures of petroleum and nonpetroleum products normally handled as liquids, and having a Reid vapor pressure of 101.325 kPa (14.696 psi) or less. Values are determined at existing temperatures and corrected to 15 °C or 60 °F by means of a series of calculations and international standard tables. 1.2 The initial hydrometer readings obtained are uncorrected hydrometer readings and not density measurements. Readings are measured on a hydrometer at either the reference temperature or at another convenient temperature, and readings are corrected for the meniscus effect, the thermal glass expansion effect, alternative calibration temperature effects and to the reference temperature by means of the Petroleum Measurement Tables; values obtained at other than the reference temperature being hydrometer readings and not density measurements. 1.3 Readings determined as density, relative density, or API gravity can be converted to equivalent values in the other units or alternative reference temperatures by means of Interconversion Procedures (API MPMS Chapter 11.5), or Adjunct to D1250 Guide for Petroleum Measurement Tables (API MPMS Chapter 11.1), or both, or tables, as applicable. 1.4 The initial hydrometer readings determined in the laboratory shall be recorded before performing any calculations. The calculations required in Section 10 shall be applied to the initial hydrometer reading with observations and results reported as required by Section 11 prior to use in a subsequent calculation procedure (ticket calculation, meter factor calculation, or base prover volume determination). 1.5 Annex A1 contains a procedure for verifying or certifying the equipment for this test method. 1.6 The values stated in SI units are to be regarded as standard. 1.6.1 Exception— The values given in parentheses are provided for information only. 1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 Accurate determination of the density, relative density (specific gravity), or API gravity of petroleum and its products is necessary for the conversion of measured volumes to volumes or masses, or both, at the standard reference temperatures of 15 °C or 60 °F during custody transfer. 5.2 This procedure is most suitable for determining the density, relative density (specific gravity), or API gravity of low viscosity transparent liquids. This procedure can also be used for viscous liquids by allowing sufficient time for the hydrometer to reach temperature equilibrium, and for opaque liquids by employing a suitable meniscus correction. Additionally for both transparent and opaque fluids the readings shall be corrected for the thermal glass expansion effect and alternative calibration temperature effects before correcting to the reference temperature. 5.3 When used in connection with bulk oil measurements, volume correction errors are minimized by observing the hydrometer reading at a temperature close to that of the bulk oil temperature. 5.4 Density, relative density, or API gravity is a factor governing the quality and pricing of crude petroleum. However, this property of petroleum is an uncertain indication of its quality unless correlated with other properties. 5.5 Density is an important quality indicator for automotive, aviation and marine fuels, where it affects storage, handling and combustion.