1、April 2009DEUTSCHE NORM Normenausschuss Materialprfung (NMP) im DINDIN-SprachendienstEnglish price group 6No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale
2、 for German Standards (DIN-Normen).ICS 75.080!$I7“1933820www.din.deDDIN 51559-2Testing of mineral oils Determination of saponification number Part 2: Colour-indicator titration, insulating oilsEnglish translation of DIN 51559-2:2009-04Prfung von Minerallen Bestimmung der Verseifungszahl Teil 2: Farb
3、indikator-Titration, IsolierleEnglische bersetzung von DIN 51559-2:2009-04Essais des huiles minrales Dtermination de lindice de saponification Partie 2: Titration en prsence dindicateurs colors, huiles isolantesTraduction anglaise de DIN 51559-2:2009-04SupersedesDIN 51559-2:1990-03www.beuth.deDocume
4、nt comprises 8 pages05.13 DIN 51559-2:2009-04 2 A comma is used as the decimal marker. Contents Page Foreword 3 1 Scope 4 2 Normative references 4 3 Terms and definitions . 4 4 Principle 4 5 Designation 4 6 Apparatus . 5 7 Reagents . 5 8 Sampling . 6 9 Procedure . 6 9.1 Sample size 6 9.2 Determinati
5、on of saponification number 6 9.3 Determination of blank value 6 10 Evaluation . 6 11 Expression of result 7 12 Precision . 7 12.1 General 7 12.2 Repeatability . 7 12.3 Reproducibility . 7 13 Test report 7 Bibliography 8 DIN 51559-2:2009-04 3 Foreword This standard has been prepared by Working Group
6、 NA 062-06-61 AA Prfung von Schmierlen, sonstigen len und Paraffinen of the Fachausschuss Minerall- und Brennstoffnormung (Standardization of petroleum, fuels, lubricants and related products committee (FAM) of the Normenausschuss Materialprfung (Materials Testing Standards Committee). DIN 51559 Tes
7、ting of mineral oils Determination of the saponification number consists of the following parts: Part 1: Saponification numbers above 2, colour-indicator titration Part 2: Colour-indicator titration, insulating oils Amendments This standard differs from DIN 51559-2:1990-03 as follows: a) when insula
8、ting oils are tested, the test method specified in this document replaces that specified in DIN 51559-2:1990-03; b) the normative references have been updated; c) the standard has been editorially revised. Previous editions DIN DVM 3659 = DIN 53659: 1932-11, 1936-02 DIN 51559: 1955-06 DIN 51559-2: 1
9、990-03 DIN 51559-2:2009-04 4 1 Scope This standard specifies a method of determining the saponifiable constituents content of insulating oils by means of the saponification number. The values determined by this test method cannot be compared with those determined in accordance with DIN 51559-1 or wi
10、th any other test methods. This standard applies to insulating oils, Baader aged in accordance with DIN 51554-2, including those containing non-mineral oil-based antioxidants (inhibitors). 2 Normative references The following referenced documents are indispensable for the application of this documen
11、t. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. DIN 51559-1, Testing of mineral oils Determination of the saponification number Part 1: Saponification numbers above 2, colour-indicator
12、titration DIN 51554-2, Testing of mineral oils Part 2: Test of susceptibility to ageing according to Baader Testing at 110 C DIN 51750-1, Sampling of petroleum products General information DIN 51750-2, Sampling of liquid petroleum products 3 Terms and definitions For the purposes of this document, t
13、he following term and definition applies. 3.1 saponification number VZ quantity of alkali, expressed in milligrams of potassium hydroxide (KOH) consumed by 1 g of a sample under the conditions specified in this standard 4 Principle A weighed sample of insulating oil is dissolved in a mixture of tolu
14、ene and ethanol containing a colour indicator. A measured volume of ethanolic potassium hydroxide solution is added and the solution then boiled. The excess potassium hydroxide solution is titrated with hydrochloric acid. The saponification number is calculated from the amount of potassium hydroxide
15、 solution consumed. 5 Designation Designation of the method of determining the saponification number by colour-indicator titration of insulating oils (A) in accordance with this standard (02): Test DIN 51559-02-A DIN 51559-2:2009-04 5 6 Apparatus 6.1 Standard laboratory apparatus 6.2 Narrow mouth co
16、nical flask, of 250 ml to 300 ml capacity, made of glass of hydrolytic resistance class HGB 1 as specified in DIN ISO 719, of acid resistance class S1 as specified in DIN 12116 and of alkali resistance class A1 as specified in DIN ISO 695. The conical flask to be used shall be made of a glass from w
17、hich traces of alkali salts cannot be leached out. Traces of alkali salts falsify the result of the determination. 6.3 Allihn condenser with conical ground joints, e.g. condenser DIN 12581-K250-29; mushroom-type condenser or immersion condenser. 6.6 Schellbach burette of 25 ml capacity, e.g. as spec
18、ified in DIN EN ISO 385, and graduated in 0,05 ml subdivisions, or equivalent equipment. 6.7 Hot plate. 7 Reagents Unless otherwise specified, only analytical grade reagents and distilled water or water of equivalent purity shall be used. 7.1 Ethanolic potassium hydroxide solution, with an amount of
19、 substance concentration of c(KOH) = 0,1 mol/l, to be prepared as follows: Add 6 g of potassium hydroxide in the form of pellets to 1 l of ethanol in a 2 l conical flask with reflux condenser. Gently boil the mixture for 10 min to 15 min while stirring, thus avoiding solids forming a cake at the bot
20、tom of the conical flask. Add at least 2 g of barium hydroxide octahydrate, O8H Ba(OH)22 and boil gently for a further 5 min to 10 min. Allow to cool and stand at room temperature (18 C to 28 C) for several hours. Filter the clear supernatant liquid using a sintered disc filter funnel made of fine s
21、intered glass or porcelain. Avoid unnecessary contact with the carbon dioxide from the air. Store the ethanolic potassium hydroxide solution in a chemically resistant (alkali resistant) bottle out of contact with cork, rubber or saponifiable stopcock lubricant. Protect its stability by a guard tube
22、containing soda lime. Check the titre of the ethanolic potassium hydroxide solution frequently to detect changes in the amount of substance concentration of 0,000 5 mol/l. For this purpose, dissolve pure potassium hydrogen phtalate in approximately 100 ml of water free of carbon dioxide and use phen
23、olphthalein as the indicator. For the preparation of the ethanolic potassium hydroxide solution, c(KOH) = 0,1 mol/l, a concentrate from an ampoule may also be used. For this purpose, rinse the contents of the ampoule with ethanol in a 1 l volumetric flask. Then fill the 1 l measuring flask almost up
24、 to the mark with ethanol, shake and make up precisely to the mark. Homogenize the solution by shaking again. Commercially prepared ethanolic potassium hydroxide solutions, c(KOH) = 0,1 mol/l, may also be used. 7.2 Titration solvent, to be prepared as follows: Dissolve 0,9 g of alkali blue 6 B in 1
25、000 ml of ethanol. Add 1 250 ml of toluene and shake the solution. Keep the solution in a sealed vessel. After 12 h filter the blank solution in order to remove any existing settlings, e.g. traces of undissolved colouring matter. 7.3 Hydrochloric acid, c(HCl) = 0,1 mol/l. DIN 51559-2:2009-04 6 8 Sam
26、pling In accordance with DIN 51750-1 and DIN 51750-2. 9 Procedure 9.1 Sample size Choose the size of the sample so that at least 50 % of the ethanolic potassium hydroxide solution is consumed, but take care not to exceed a sample size of 20 g. 9.2 Determination of saponification number Weigh the sam
27、ple to the nearest 0,01 g into a 300 ml conical flask. Add at least 40 ml of titration solvent. Following the dissolution of the sample, add (25 0,03) ml ethanolic potassium hydroxide solution, c(KOH) = 0,1 mol/l. Connect the condenser to the flask and bring the solution to a boil and keep it boilin
28、g for 30 min under reflux conditions. Then titrate the solution while hot, without reboiling, with hydrochloric acid, c(HCl) = 0,1 mol/l. The end point is reached when the indicator turns from red to blue. NOTE To sensitize the indicator, it is recommended to add one drop of hydrochloric acid, c(HCl
29、) = 0,1 mol/l, to the titration solution prior to dissolving the oil sample and neutralize with ethanolic potassium hydroxide solution, c(KOH) = 0,1 mol/l. 9.3 Determination of blank value It is necessary to perform a blank determination with each set of samples. Add the same volume of titration sol
30、vent as used for the determination (25 0,03) ml and ethanolic potassium hydroxide solution, c(KOH) = 0,1 mol/l, to the conical flask. Then proceed as specified in 9.2. For referee tests, carry out blank determinations in duplicate. 10 Evaluation The saponification number VZ, in mg KOH/g of oil, is c
31、alculated using the following equation: E121,56)()(mHClcVVVZ= where VZ is the saponification number in mg KOH/g; V1is the volume of hydrochloric acid, c(HCl) = 0,1 mol/l, in ml required for titration of the test solution (see 9.2); V2is the volume of hydrochloric acid, c(HCl) = 0,1 mol/l, in ml requ
32、ired for titration of the blank solution (see 9.3); mEis the initial sample mass, in g. DIN 51559-2:2009-04 7 11 Expression of result Indicate the saponification number VZ, in mg KOH/g of oil, with a reference to this standard. Report the results rounded to two decimal places. 12 Precision 12.1 Gene
33、ral The precision data are currently determined in interlaboratory tests. 12.2 Repeatability The difference between two results, obtained by the same operator with the same apparatus under constant operating conditions on identical test material would in the long run, in the normal and correct opera
34、tion of the test method exceed the values given in the tables in only one case in twenty. 12.3 Reproducibility The difference between two single and independent results, obtained by different operators working in different laboratories on identical test materials would in the long run, in the normal
35、 and correct operation of the test method exceed the values given in the tables in only one case in twenty. 13 Test report The test report shall contain at least the following information: a) a reference to this standard; b) the type and complete identification of the product tested; c) the results
36、of the test in accordance with Clause 11; d) any deviation, by agreement or otherwise, from the standard procedures specified; e) the date of the test. DIN 51559-2:2009-04 8 Bibliography DIN ISO 719, Glass Hydrolytic resistance of glass grains at 98 C Method of test and classification DIN 12116, Tes
37、ting of glass Resistance to attack by a boiling aqueous solution of hydrochloric acid Method of test and classification DIN 12581, Laboratory glassware Allihn condensers with standard ground joints DIN EN ISO 385, Laboratory glassware Burettes DIN ISO 695, Glass Resistance to attack by a boiling aqueous solution of mixed alkali Method of test and classification
