1、DEUTSCHE NORM June 1999 I DIN Oscillation-type density meters Part 1 : Laboratorv instruments (IS0 1521 2- : 1998) Enalish version of DIN EN IS0 15212-1 IEN IS0 1521 2-1 ICs 17.060 Dichtemegerte nach dem Schwingerprinzip - Teil 1 : Laborgerte (IS0 1521 2-1 : 1998) European Standard EN IS0 15212-1 :
2、1999 has the status of a DIN Standard. A comma is used as the decimal marker. National foreword This standard has been published in accordance with a decision taken by CEN/TC 332 to adopt, without alteration, International Standard IS0 1521 2-1 as a European Standard. The responsible German body inv
3、olved in its preparation was the Normenausschu Laborgerate und aboreinrichtungen (Laboratory Equipment Standards Committee), Technical Committee Dichtemegerate auf Schwingerbasis. The DIN Standards corresponding to the International Standards and IEC publications referred to in clause 2 of the EN ar
4、e as follows: IEC Publication/lSO Standard DIN Standard IEC 61 O1 0-1 IEC 61 326-1 DIN EN 61 O1 0-1 DIN EN 61326-1 IS0 3585 DIN IS0 3585 IS0 3696 DIN IS0 3696 National Annex NA Standards referred to (and not included in Normative references and Annex ZA) DIN EN 61 O1 0-1 DIN EN 61326-1 Safety requir
5、ements for electrical equipment for measurement, control and laboratory use - Part 1 : General requirements (IEC 61 O1 0-1 : 1990 + Al : 1992, modified) Electrical equipment for measurement, control and laboratory use - EMC requirements - Part 1 : General requirements (IEC 61 326-1 : 1997) EN compri
6、ses 23 pages. No pari of this standard may be reproduced without the prior permission of Ref. No. DIN EN IS0 15212-1 : 1999-0 V Deutsches Institut fur Normung e. V., Berlin. Luth Verlag GmbH, D-10772 Berlin, has the exclusive right of sale for German Standards (DIN-Normen). English pricegroup 10 Sal
7、es No. 1110 o1 .o0 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN IS0 1521 2-1 March 1999 ICs 17.060 English version Oscillation-type density meters Part 1 : Laboratory instruments (IS0 1521 2-1 : 1998) Densimtres oscillations - Partie 1 : Instruments de laboratoire (IS0 15212-1 : 1998) Dichte
8、megerte nach dem Schwingerprinzip - Teil 1 : Labor- gerate (IS0 15212-1 : 1998) This European Standard was approved by CEN on 1999-03-03. CEN members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national
9、 standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. The European Standards exist in three official versions (English, French, German). A version in any oth
10、er language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, the Czech Republic, Denmark, Finland, France, German
11、y, Greece, Iceland, Ireland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels O 1
12、999. CEN - All rights of exploitation in any form and by any means reserved worldwide for CEN national members. Ref. No. EN IS0 15212-1 : 1999 E Page 2 EN IS0 15212-1 : 1999 Foreword International Standard IS0 1521 2-1 : 1998 Oscillation-type density meters - Part 1 : Laboratory instruments, which w
13、as prepared by ISO/TC 48 Laboratory glassware and related apparatus of the International Organization for Standardization, has been adopted by Technical Committee CEN/TC 332 Laboratory equipment, the Secretariat of which is held by DIN, as a European Standard. This European Standard shall be given t
14、he status of a national standard, either by publication of an identical text or by endorsement, and conflicting national standards withdrawn, by September 1999 at the latest. In accordance with the CENKENELEC Internal Regulations, the national standards organizations of the following countries are b
15、ound to implement this European Standard: Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom. Endorsement notice The text of the International Stan
16、dard IS0 15212-1 : 1998 was approved by CEN as a European Standard without any modification. NOTE: Normative references to international publications are listed in Annex ZA (normative). Contents Page 1 Scope 3 2 Normative references 3 3 Definitions 4 4 Principle and functional units 4 4.1 Measuring
17、principle 4 4.2 Functional units 4 5 Density sensor 5 . 5.1 Sensor material . 5 5.2 Sensor design . 5 6 Requirements and tests 6 6.1 Oscillation system 6 6.2 Temperature control and measurement . 7 . 6.3 Displays 9 . 6.4 Auxiliary units and data transfer 9 6.5 Safety requirements . 1 0 6.6 Electroma
18、gnetic compatibility . 10 7 Adjustment . 1 O 8 Calibration 1 O 8.1 Density reference liquids , 1 O 8.2 Particular density reference liquids 11 Page 3 EN IS0 15212-1 : 1999 8.3 Calibration requirements 11 8.4 Calibration procedure 11 9 Density meter accuracy 12 10 Manual 12 11 Marking . 13 Annex A (n
19、ormative) Density and compressibility of pure water 14 Annex B (normative) Density of moist air 19 Annex C (informative) Bibliography 22 1 Scope This part of IS0 15212 specifies metrological and other requirements for oscillation-type density meters which are used in laboratories for all kinds of ho
20、mogeneous fluid samples. In addition, a method for adjustment and calibration of laboratory instruments is given. The instruments are either stand-alone units or part of more complex measuring equipment supplying additional test parameters of the sample. This part of IS0 15212 does not describe the
21、method of use of density meters for particular applications or products such as petroleum products or beverages. Such methods of use can be defined by relevant institutions such as IS0 or responsible government agencies. This part of IS0 15212 does not define an instrument specification for any part
22、icular application. For this information reference should be made to the relevant standard covering the method of use. This pari of IS0 15212 is addressed to manufacturers of density meters and to bodies testing and certifying the conformity of density meters. In addition, this part of IS0 15212 giv
23、es recommendations for adjustment and calibration of density meters by the user. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of IS0 15212. At the time of publication, the editions indicated were valid. Al
24、l standards are subject to revision, and parties to agreements based on this part of IS0 15212 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain registers of currently valid International Standards. IS
25、0 35851 998, Borosilicate glass 3.3 - Properties. IS0 3696: 1987, Water for analytical laboratory use - Specification and test methods. IEC 61 O1 0-1 : 1990, Safety requirements for electrical equipment for measurement, control and laboratory use - Par 1: General requirements. IEC 61326-1:1997, Elec
26、trical equipment for measurement, control and laboratory use - EMC requirements - Part 1: General requirements. IEC 61326-1 :-I), Amendment 1. 1) To be published. Page 4 EN IS0 15212-1 : 1999 3 Definitions For the purposes of this part of IS0 15212, the following definitions apply. NOTE Metrology: 3
27、.1 adjustment (of a density meter) operation of bringing the instrument to a state of performance suitable for its use, by setting or adjusting the density instrument constants The definitions and terms used are in agreement with the “International Vocabulary of Basic and General Terms in NOTE appli
28、cation. Adjustment demands an intervention which permanently modifies the instrment. By adjustment, systematic measuring deviations are removed to an extent which is necessary for the provided 3.2 calibration (of a density meter) set of operations that establishes the relationship between the refere
29、nce density of standards and the corresponding density reading of the instrument NOTE during the adjustment procedure. By calibration, no intervention is made which permanently modifies, for example, the instrument constants set 3.3 parasitic resonant points (of a density meter) those oscillation fr
30、equencies at which the natural frequency of the density sensor is affected by oscillations of the “counter mass“, comprising the rest of the instrument 4 Principle and functional units 4.1 Measuring principle The sensors used in density meters are electrically or mechanically induced oscillating sys
31、tems, whose oscillation frequencies or periods are a function of the sample density. Depending on the sensor design, the sensor can either contain the fluid sample or be immersed in it. Instrument constants of the adjusted density meter are used to calculate the sample density from the oscillation f
32、requency or oscillation period. 4.2 Functional units Oscillation-type density meters shall consist of the following functional units: a) b) c) d) e) The functional units a) to c) are designated as the oscillation system. In addition, oscillation-type density meters can incorporate the following func
33、tional units: f) g) sampling devices; h) sensor cleaning devices. All functional units a) to h) can be integrated into a single instrument or can be separate units. a density sensor capable of either being filled with the sample or of being immersed in it; a device to excite and control sensor oscil
34、lation; a device to determine and display the density and the oscillation frequency or period: a device to determine and display the sample temperature for which the measured density is valid; a system to detect and display malfunctions and operator errors. a unit for controlling the temperature of
35、the sample and density sensor: Page 5 EN IS0 15212-1 : 1999 - Sample - 4-1 Temperature Malfunction r-l : I-1 I 1 I I I 1 B , i) A I Display Density Key A Density sensor (4.2a) B Excitation transmitter (4.2b) C Signal evaluation (4.2) D Temperature measurement (4.2d) E Functional monitoring (4.2e) Fi
36、gure 1 - Functional units of a density meter 5 Density sensor 5.1 Sensor material Density sensor materials can be, for example, borosilicate glass 3.3 in accordance with IS0 3585, metal, metal alloys or plastics. The material is considered to be suitable if it shows in resistance tables the highest
37、class of resistance against the samples to be measured and the cleaning agents to be used in the density meter. Erosion as well as special forms of corrosion shall be considered in this respect. Where there is no literature or practical data available, the resistance of the sensor material should be
38、 tested as follows. a) Weigh a clean and dry test piece identical to the sensor material. The maximum permissible error of the balance shall not exceed 0,Ol % of the test-piece mass. b) Immerse the test piece in the fluid to be measured with the sensor, under the intended measuring conditions, e.g.
39、temperature and pressure. c) The sensor material is considered to be resistant if the mass of the test piece is changed by the test procedure by less than 0,05 %. After 12 h remove, clean, dry and weigh the test piece. 5.2 Sensor design Density sensors can be designed as straight, U-formed or omega-
40、formed tubes. Other designs are tuning-forks, cylinders, bells or membranes. All designs which conform to the functional principle in accordance with 4.1 can be constructed. Page 6 EN IS0 15212-1 : 1999 6 Requirements and tests All the tests of clause 6 are intended to be type tests. 6.1 Oscillation
41、 system 6.1.1 Drift 6.1.1.1 Within 24 h, the drift of the displayed density Ap24 at a constant temperature of 20 OC shall not exceed 1 % of the maximum permissible error specified by the manufacturer of the instrument. If the density meter is not designed for a measuring temperature of 20 “C, the dr
42、ift at the mean measuring temperature of the density meter shall not exceed 5 % of the specified maximum permissible error. 6.1.1.2 Switch on the instrument and allow the temperature to equilibrate for 24 h. Adjust the instrument (see clause 7) in accordance with the manufacturers instructions. Fill
43、 the instrument three times and measure the density of water of Grade 2 in accordance with IS0 3696 at (20 - attemperate the instrument for 24 h; - precondition to 30 “C a reference liquid with high thermal density dependency; - fill the density sensor with the preconditioned reference liquid. Page
44、7 EN IS0 15212-1 : 1999 The first density value displayed by the instrument as valid or read from the instrument after a time period specified by the manufacturer is compared with the density value displayed after 10 min. The difference between the two values shall not exceed 20 % of the maximum per
45、missible error specified for the density meter by the manufacturer. NOTE Bromobenzene or n-nonane are suitable examples of reference liquids for this test. Warning: Bromobenzene is a hazardous substance and may not be permitted under Safety Regulations. If the density meter is not designed for a mea
46、suring temperature of 20 OC, testing shall be performed at the mean measuring temperature of the density meter. 6.1.4 Effect of oscillations 6.1.4.1 Measurement deviations arising from the effect of oscillations of instrument parts on the density sensor shall not exceed 20 % of the maximum permissib
47、le error, specified for the density meter by the manufacturer, over the whole meas ur ng range. 6.1.4.2 Examine the oscillatory characteristics of the built-in density sensor provided by the manufacturer. This test may not show, over the whole density measurement range, any parasitic resonant points
48、 (see 3.3) whose effects exceed 20 % of the maximum permissible error specified for the density meter by the manufacturer. 6.2 Temperature control and measurement 6.2.1 Requirement The temperature sensor shall be built-in or a separate temperature unit shall be fitted in such a way that good thermal
49、 contact with the sample is guaranteed. The deviation between the displayed and actual sample temperatures shall not be greater than the maximum permissible error of the density meter multiplied by the factor 0,2 “C.kg-l.m3. NOTE If the application range of the density meter is limited to aqueous samples and water-containing mixtures, the factor to be multiplied by the maximum permissible error can be increased to 0,5 “C kg-1113. 6.2.2 Test conditions For the definition of this factor, an extreme thermal density deviation of 2,4 kg m-3.K-1 has been assumed. The mea
