Standard Test Method for Density, Relative Density, and ...

1 Designation: D4052 11 Standard Test Method forDensity, Relative density , and API Gravity of Liquids byDigital density Meter1 This Standard is issued under the fixed designation D4052; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon ( ) indicates an editorial change since the last revision or Standard has been approved for use by agencies of the Department of Scope* This test Method covers the determination of the Density, Relative density , and API Gravity of petroleum distillates andviscous oils that can be handled in a normal fashion as liquidsat the temperature of test, utilizing either manual or automatedsample injection equipment. Its application is restricted toliquids with total vapor pressures (see Test MethodD5191)typically below 100 kPa and viscosities (see Test MethodD445orD7042) typically below about 15 000 mm2/s at the tempera-ture of test.

2 The total vapor pressure limitation however can beextended to >100 kPa provided that it is first ascertained that nobubbles form in the U-shaped, oscillating tube, which canaffect the density determination. Some examples of productsthat may be tested by this procedure include: gasoline andgasoline-oxygenate blends, diesel, jet, basestocks, waxes, andlubricating Waxes and highly viscous samples were not includedin the 1999 interlaboratory study (ILS) sample set that wasused to determine the current precision statements of themethod, since all samples evaluated at the time were analyzedat a test temperature of 15 C. Wax and highly viscous samplesrequire a temperature cell operated at elevated temperaturesnecessary to ensure a liquid test specimen is introduced foranalysis. Consult instrument manufacturer instructions forappropriate guidance and precautions when attempting toanalyze wax or highly viscous samples. Refer to the Precisionand Bias section of the Method andNote 8for more detailedinformation about the 1999 ILS that was In cases of dispute, the referee Method is the one wheresamples are introduced manually as , as appropri-ate for sample This test Method should not be applied to samples sodark in color that the absence of air bubbles in the sample cellcannot be established with certainty.

3 For the determination ofdensity in crude oil samples use Test The values stated in SI units are regarded as thestandard, unless stated otherwise, such as the torr units ofpressure in Eq 1. The accepted units of measure for density aregrams per millilitre (g/mL) or kilograms per cubic metre(kg/m3). Standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this Standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to specificwarning statements, , , Referenced Standards:2D287 Test Method for API Gravity of Crude Petroleum andPetroleum Products (Hydrometer Method )D445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D1193 Specification for Reagent WaterD1250 Guide for Use of the Petroleum Measurement TablesD1298 Test Method for density , Relative density (SpecificGravity), or API Gravity of Crude Petroleum and LiquidPetroleum Products by Hydrometer MethodD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD4377 Test Method for Water in Crude Oils by Potentio-metric Karl Fischer TitrationD5002 Test Method for density and Relative density ofCrude Oils by Digital density AnalyzerD5191 Test Method for Vapor Pressure of Petroleum Prod-ucts (Mini Method )D7042 Test Method for Dynamic Viscosity and density ofLiquids by Stabinger Viscometer (and the Calculation ofKinematic Viscosity)

4 1 This test Method is under the jurisdiction of ASTM CommitteeD02onPetroleum Products and Lubricants and is the direct responsibility of Physical and Chemical edition approved Oct. 15, 2011. Published December 2011. Originallyapproved in 1981. Last previous edition approved in 2009 as D4052 09. referenced ASTM standards, visit the ASTM website, , orcontact ASTM Customer Service at ForAnnual Book of ASTMS tandardsvolume information, refer to the Standard s Document Summary page onthe ASTM *A Summary of Changes section appears at the end of this ASTM International, 100 Barr Harbor Drive, Box C700, West Conshohocken Pennsylvania 19428-2959, United States Copyright by ASTM Int'l (all rights reserved); Tue Apr 17 13:45:28 EDT 2012 Downloaded/printed byDave Astrauckas () pursuant to License Agreement. No further reproductions ,n mass per unit volume at a Density, n the ratio of the density of amaterial at a stated temperature to the density of water at astated of Terms Specific to This ,v the operation of bringing the instru-ment to a state of performance suitable for its use, by setting oradjusting the density meter On some digital density analyzer in-struments, an adjustment may be made rather than calibratingthe instrument.

5 The adjustment procedure uses air and redis-tilled, freshly boiled water (Warning Handling water atboiling or near boiling temperature can present a safety appropriate personal protective equipment.) as standardsto establish the linearity of measurements over a range ofoperating ,v set of operations that establishes therelationship between the reference density of standards and thecorresponding density reading of the Summary of Test A small volume (approximately 1 to 2 mL) of liquidsample is introduced into an oscillating sample tube and thechange in oscillating frequency caused by the change in themass of the tube is used in conjunction with calibration data todetermine the density , Relative density , or API Gravity of thesample. Both manual and automated injection techniques Significance and density is a fundamental physical property that can beused in conjunction with other properties to characterize boththe light and heavy fractions of petroleum and Determination of the density or Relative density ofpetroleum and its products is necessary for the conversion ofmeasured volumes to volumes at the Standard temperature of15 density Analyzer A digital analyzer consistingof a U-shaped, oscillating sample tube and a system forelectronic excitation, frequency counting, and display.

6 Theanalyzer shall accommodate the accurate measurement of thesample temperature during measurement or shall control thesample temperature as described The instrument shall becapable of meeting the precision requirements described in thistest Constant-Temperature Bath, (optional), ca-pable of maintaining the temperature of the circulating liquidconstant C in the desired range. Temperature controlcan be maintained as part of the density analyzer , for use primarily in manual injections, at least2 mL in volume with a tip or an adapter tip that will fit theopening of the oscillating or Pressure Adapter, for use as analternative means of introducing the sample into the densityanalyzer either by a pump, by pressure, or by It is highly recommended that a vacuum not be applied tosamples prone to light-end loss, as it can easily lead to the formation ofbubbles. It is recommended to fabricate a special cap or stopper for samplecontainers so that air, such as from a squeeze pump, is used to displace atest specimen to the U-tube measuring cell by the flow-through , required for use in automated injectionanalyses.

7 The autosampler shall be designed to ensure theintegrity of the test specimen prior to and during the analysisand be equipped to transfer a representative portion of testspecimen to the digital density Sensing Device (TSD), capable of monitor-ing the observed test temperature to within an accuracy C. If a liquid-in-glass thermometer is used as the TSD,it shall be calibrated and graduated to C, and have a holderthat can be attached to the instrument for setting and observingthe test temperature. In calibrating the thermometer, the icepoint and bore connections should be estimated to the C. For non-mercurial thermometers, the TSD device shallbe calibrated at least annually against a certified and Bath, Unheated, (optional), of suitable di-mensions to hold container(s) placed inside of bath, for use ineffectively dissipating and removing air or gas bubbles thatmay be entrained in viscous sample types prior to Reagents and of Reagents Reagent grade chemicals shall beused in all tests.

8 Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the of Water Unless otherwise indicated, referencesto water shall be understood to mean reagent water as definedby Type II of SpecificationD1193or , redistilled, freshly boiled (Warning Handlingwater at boiling or near boiling temperature can present asafety hazard. Wear appropriate personal protective equip-ment.) reagent water for use as a primary calibration Solvent, such as petroleum naphtha4(Warning Petroleum naphtha is extremely flammable), orother materials that are capable of flushing and removingsamples entirely from the sample , for flushing and drying the sample tube.(Warning Extremely flammable.)3 Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC.

9 For suggestions on the testing of reagents notlisted by the American Chemical Society, seeAnalar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, , and theUnited States Pharmacopeiaand National Formulary, Pharmaceutical Convention, Inc. (USPC), Rockville, solvent naphthas are marketed under various designations such as Petroleum Ether, Ligroine, or Precipitation Naphtha. D4052 112 Copyright by ASTM Int'l (all rights reserved); Tue Apr 17 13:45:28 EDT 2012 Downloaded/printed byDave Astrauckas () pursuant to License Agreement. No further reproductions Air, for drying the oscillator Sampling, Test Specimens, and Test Sampling is defined as all the steps required to obtain analiquot of the contents of any pipe, tank, or other system, andto place the sample into the laboratory test container. Thelaboratory test container and sample volume shall be ofsufficient capacity to mix the sample and obtain a homoge-neous sample for Sample Use only representative samplesobtained as specified in PracticesD4057orD4177for this Specimen A portion or volume of sample obtainedfrom the laboratory sample and delivered to the densityanalyzer sample tube.

10 The test specimen is obtained as Mix the sample if required to homogenize taking careto avoid the introduction of air bubbles. The mixing may beaccomplished as described in PracticeD4177or Test MethodD4377. Mixing at room temperature in an open container canresult in the loss of volatile material from certain sample types(for example, gasoline samples), so mixing in closed, pressur-ized containers or at least 10 C below ambient temperature isrequired for such sample types where loss of volatile materialis a potential concern. For some sample types, such as viscouslube oils that are prone to having entrained air or gas bubblespresent in the sample, the use of an ultrasonic bath ( )without the heater turned on (if so equipped), has been foundeffective in dissipating bubbles typically within 10 When mixing samples with volatile components, consider thesample properties in relation to both ambient temperature and For manual injections, draw the test specimen from aproperly mixed laboratory sample using an appropriate sy-ringe.