1. Scope 1.1 These test methods cover the determination of the hydrogen content of petroleum products ranging from atmospheric distillates to vacuum residua using a continuous wave, low-resolution nuclear magnetic resonance spectrometer. (Test Method D3701 is the preferred method for determining the hydrogen content of aviation turbine fuels using nuclear magnetic resonance spectroscopy.) 1.2 Three test methods are included here that account for the special characteristics of different petroleum products and apply to the following distillation ranges: Boiling Range, [deg]C ([deg]F) Test Method Petroleum Products (approximate) A Light Distillates 15-260 (60-500) B Middle Distillates, 200-370 (400-700) Gas Oils 370-510 (700-950) C Residua 510+ (950+) 1.3 The preferred units are mass percent. 1.4 This standard does not purport to address all of the safety problems, 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. For specific hazard statements, see Section 6.1.