ASTM_F_862_-_11.pdf

Designation:F86211Standard Practice forpH and Chloride-ion Concentration of Aerospace HydraulicFluids1This standard is issued under the fixed designation F862;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers the measurement of the pH andchloride ion of water extraction of aerospace hydraulic fluids.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 This 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 use.2.Referenced Documents2.1 ASTM Standards:2D512 Test Methods for Chloride Ion In WaterD1193 Specification for Reagent WaterE70 Test Method for pH of Aqueous Solutions With theGlass Electrode3.Summary of Method3.1 The aerospace hydraulic fluid sample is shaken withwater,and the pH and the quantity of chloride ion aredetermined from the water layer.3.1.1 The pH is measured using a glass electrode and pHmeter.3.1.2 The quantity of the chloride ion is determined using achloride selective ion electrode and a selective ion meter.4.Significance and Use4.1 On application of the hydraulic fluid within the me-chanical fluidic system,the fluid may become contaminatedwith acid and chloride ion.Mechanical shearing of the hydrau-lic fluid in the presence of the minute quantity of water andresidual amount of organic solvents,used in cleaning,mayinitiate formation of acid and chloride ion.Measurements aredesired to control and maintain the cleanliness and non-corrosiveness of the fluidic system.5.Apparatus5.1 Combination pH Selective Ion Meter,5.2 Glass ElectrodeThe pH response shall be 60.05 pH.5.3 Reference ElectrodeA calomel,silver/silver chloride,or other reference electrode of constant potential.5.4 Chloride Selective Ion Electrode.5.5 Double Junction Reference Electrode,sleeve-type5.6 Separatory Funnel,250 mL.6.Reagents6.1 Water,reagent grade,Type IV,in accordance withSpecification D1193.6.2 ReferenceBufferSolutions,SRM/RM 185,186,and 187Materials supplied by the National Institute of Stan-dards and Technology with pH values.7.Standardization of pH Meter7.1 Standardize the pH meter in accordance with TestMethod E70.PART ApH MEASUREMENT8.Procedure8.1 Add a 50-mL sample of hydraulic fluid and 50 mL ofreagent water to a 250-mL separatory funnel.8.2 Mix thoroughly.Allow for the water and oil layers toseparate completely.8.3 Drain the water layer from the funnel into a 100-mLbeaker.8.4 Standardize the pH-meter assembly with two referencebuffer solutions as described in section 7.1.Wash the electrodeswith three changes of water.Equip the beaker with a small1This practice is under the jurisdiction of ASTM Committee F07 on Aerospaceand Aircraft and is the direct responsibility of Subcommittee F07.07 on Qualifica-tion Testing of Aircraft Cleaning Materials.Current edition approved Dec.1,2011.Published January 2012.Originallyapproved in 1984.Last previous edition approved in 2002 as F862 93(2002)which was withdrawn January 2011 and reinstated in December 2011.DOI:10.1520/F0862-11.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 laboratory-type mechanical stirrer having a glass agitator orwith a magnetic stirring unit having an inert,plastic-coveredimpeller.Insert the electrodes and determine the pH value;measure the water sample until two readings 30 s apart do notdiffer by more than 0.05-pH unit.Record the pH values.9.Calculation9.1 The pH of the sample is the average of the last tworeadings.10.Report10.1 Report the pH of the water extraction of hydraulic fluidto the nearest 0.1 unit.11.Precision and Bias11.1 See Test Method E70 for Precision and Bias informa-tion.PART BCHLORIDE-ION CONCENTRATIONMEASUREMENT12.Procedure12.1 Add a 100-mLsample of hydraulic fluid and 100 mLofreagent water to a 250-mL separatory funnel.12.2 Mix thoroughly.Allow for the water and oil layers toseparate completely.12.3 Drain the water layer from the funnel into a 250-mLbeaker.12.4 Prepare a calibration curve and determine the chlorideion concentration on the water layer in accordance with D512Test Method C.13.Calculation13.1 Read the chloride ion concentration directly from thecalibration curve prepared in section 12.4.14.Report14.1 Report the chloride-ion concentration to the nearestwhole integer.15.