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ASTM D1657

Standard Test Method for Density or Relative Density of Light Hydrocarbons by Pressure Hydrometer
This test method covers the determination of the density or relative density of light hydrocarbons including liquefied petroleum gases (LPG) having Reid vapor pressures exceeding 101.325 kPa (14.696 psi).
The prescribed apparatus should not be used for materials having vapor pressures higher than 1.4 MPa (200 psi) at the test temperature. This pressure limit is dictated by the type of equipment. Higher pressures can apply to other equipment designs.
The initial pressure 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, alternate calibration temperature effects and to the reference temperature by means of calculations and Adjunct to D1250 Guide for Petroleum Measurement Tables (API MPMS Chapter 11.1) or API MPMS Chapter 11.2.4 (GPA TP-27), as applicable.
Values determined as density or relative density 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 API MPMS Chapter 11.2.4 (GPA TP-27), as applicable.
The calculations required in Section 11 shall be applied to the initial pressure hydrometer reading with observations and results reported as required by Section 11 prior to use in a subsequent calculation procedure (measurement ticket calculation, meter factor calculation, or base prover volume determination).

IP 235

Determination of density of light hydrocarbons - Pressure hydrometer method
This method provides a procedure for determining the density of light hydrocarbons including liquefied petroleum gases. The prescribed apparatus should not be used for materials having vapour pressures higher than 14 bar at the test temperature.

ISO 3993

Liquefied petroleum gas and light hydrocarbons -- Determination of density or relative density -- Pressure hydrometer method
The prescribed apparatus shall not be used for materials having gauge vapour pressures higher than 1,4 MPa (absolute vapour pressure 1,5 MPa) at the test temperature. Alternative calibration procedures are described, but only the one using a certified hydrometer is suitable for the determination of density to be used in calculations of qualities for custody transfer or fiscal purposes.

 

 

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