【国外标准】 Standard Test Method for Methyl Hydrogen Content of Hydrocarbon Oils by High Resolution Nuclear Magnetic Resonance Spectroscopy

5.1 Methyl hydrogen content is a key characteristic of hydrocarbon lubricating oils and can affect a variety of properties of the oil including its boiling range, viscosity, low temperature flow, and oxidation stability.5.2 The NMR procedure does not require calibration standards of known methyl hydrogen content and is applicable to a wide range of hydrocarbon lubricating oils that are completely soluble in chloroform at ambient temperature.1.1 This test method covers the determination of the total methyl hydrogen content of unadditized base stock (lubricating oils) hydrocarbon oils that are completely soluble in chloroform at ambient temperature using high-resolution nuclear magnetic resonance (NMR) spectrometers.1.2 The reported units are mol percent methyl hydrogen atoms. For pulse Fourier transform (FT) spectrometers, the detection limit is typically 0.1 % mol hydrogen atoms. The interim precision is applicable in the range 20.5 % to 38.7 % mol methyl hydrogen.1.3 This method is applicable to samples containing <0.1 % mol olefinic hydrogens.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in 7.2 and 7.3.1.6 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.