1、Designation: F 862 93 (Reapproved 2002)Standard Test Method forpH and Chloride-ion Concentration of Aerospace HydraulicFluids1This standard is issued under the fixed designation F 862; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision
2、, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the measurement of the pH andchloride ion of water extraction of aerospace hydr
3、aulic fluids.1.2 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.
4、 Referenced Documents2.1 ASTM Standards:D 1193 Specification for Reagent Water23. 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
5、.3.1.2 The quantity of the chloride ion is determined using asilver/sulfide electrode and a specific 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 t
6、he 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 noncorro-siveness of the fluidic system.5. Apparatus5.1 pH
7、 Meter, with expanded millivolt scale and a sensitiv-ity of 1 mV. The method can be adopted for use with aselective-ion meter.35.2 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 Silver/S
8、ilver Sulfide Electrode.45.5 Double Junction Reference Electrode, sleeve-type.55.6 Separatory Funnel, 250 mL.5.7 Buret, 10-mL capacity.5.8 Titration Stand, preferably built as an integral part of themeter housing and provided with support for the electrodes andelectrical stimer, all connected to gro
9、und.5.9 Grans Plot Paper.66. Reagents6.1 Water, reagent grade, Type IV, in accordance withSpecification D 1193.6.2 Reference Buffer Solutions, Standards 185, 186,and 187Materials supplied by the National Bureau of Stan-dards with pH values.6.3 Silver Nitrate Solution, Standard (2.82 3 103M)Dissolve
10、4.7909 g of silver nitrate dissolved in 1 L of water anddiluted 1:10.7. Standardization of pH Meter7.1 Turn on the instrument, allow it to warm up thoroughly,and bring it to electrical balance in accordance with themanufacturers instructions. Wash the glass and referenceelectrodes with three changes
11、 of water. Form a fresh liquidjunction if a sleeve-type reference junction is used.7.2 Fill the sample cup with the first reference buffersolution and immerse the electrodes. If the pH meter is of thezero-null type, set the dial of the meter to equal pH value of thereference buffer solution. Engage
12、the operating button androtate the standardization knob until the meter is brought tobalance. If the pH meter is of the direct-reading type, engagethe operating button, turn the range switch to the properposition, and rotate the asymmetry-potential knob until thereading corresponds to the pH of the
13、reference buffer. Emptythe sample cup and repeat until two successive readings areobtained without adjustment of the controls.1This test method is under the jurisdiction of ASTM Committee F07 onAerospace and Aircraft and is the direct responsibility of Subcommittee F07.07 onQualification Testing of
14、Aircraft Cleaning Materials.Current edition approved Jan. 15, 1993. Published April 1993. Originallypublished as F 862 84. Last previous edition F 862 84.2Annual Book of ASTM Standards, Vol 11.01.3The Orion Model 901 has been found satisfactory.4The Orion Research Model has been found satisfactory.5
15、The Orion Model 90-01 has been found satisfactory.6Grans plot paper is available from Orion Research, Inc., 380 Putnam Ave.,Cambridge, MA 02139.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.3 Wash the electrodes and the sample cu
16、p three times withwater. Place the second reference buffer solution in the samplecup and measure the pH, either by simply reading the dial or byadjusting the balance point, depending on the type of pH meter.Adjust the slope control until the reading corresponds to thetemperature corrected value of t
17、he second reference buffersolution. Use additional portions of the second reference buffersolution, as in 7.2.7.4 The assembly is operating satisfactorily if the pHreading obtained for the second reference buffer solutionagrees with its assigned pH value within 0.05 units.PART ApH MEASUREMENT8. Proc
18、edure8.1 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 referencebu
19、ffer solutions as described in 7.1-7.4. Wash the electrodeswith three changes of water. Equip the beaker with a smalllaboratory-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;m
20、easure 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. Precisio
21、n and Bias11.1 A program to establish the precision and bias of thistest method will be conducted at a later date.PART BCHLORIDE-ION CONCENTRATIONMEASUREMENT12. Procedure12.1 Add a 100-mL sample of hydraulic fluid and 100 mL ofreagent water to a 250-mL separatory funnel.12.2 Mix thoroughly. Allow fo
22、r the water and oil layers toseparate completely.12.3 Drain the water layer from the funnel into a 250-mLbeaker.12.4 Equip the beaker with a small laboratory-type me-chanical stirrer having a glass agitator or with a magneticstirring unit having an inert, plastic-covered impeller. Immersethe double-
23、junction reference electrode and the silver/silversulfide electrode in the solution.12.5 Add 5.0 mL of silver nitrate standard solution from a10-mL buret. Record millivolt reading when stable.12.6 Add 1.0-mL increments of the silver nitrate standardsolution and record the millivolt reading when stab
24、le after eachaddition until a total of five have been added.13. Calculation13.1 On Grans plot paper, each major division on thevertical axis shall correspond to 5 mV. The millilitre value shallbe plotted on the horizontal axis in accordance with the wholeintegers on the paper.13.2 Calculate the chlo
25、ride-ion concentration.13.2.1 Plot on the Grans plot paper the millilitres ofstandard silver nitrate solution required for titration along thehorizontal axis of the plot paper and the correspondingmillivolt readings along the vertical axis.13.2.2 Draw a line through all points and extend to intersec
26、tthe horizontal baseline. The point at which the plotted lineintersects the baseline is equivalent to the numerical quantity ofchloride ion in the oil samples in parts per million.14. Report14.1 Report the chloride-ion concentration to the nearestwhole integer.15. Precision and Bias15.1 A program to
27、 establish the precision and bias data willbe conducted at a later date.16. Keywords16.1 chloride ion; hydraulic fluid; pHASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expre
28、ssly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised
29、, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may a
30、ttend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).F 8622
