1、BRITISH STANDARD BS EN ISO 15212-1:1999 Oscillation-type density meters Part 1: Laboratory instruments ICS 17.060 Incorporating corrigendum December 2008BSENISO15212-1:1999 This British Standard, having been prepared under the directionof the Sector Committeefor Materials and Chemicals, was publishe
2、d underthe authority of the Standards Committee and comesinto effect on 15June1999 BSI 2009 National foreword This British Standard is the UK implementaion of EN ISO 15212-1:1999. It is identical with ISO15212-1:1998, incorporating corrigendum December 2008. The start and finish of text introduced o
3、r altered by corrigendum is indicated in the text by tags. Text altered by ISO corrigendum December 2008 is indicated in the text by . The UK participation in its preparation was entrusted by Technical Committee LBI/36, Laboratory glassware and related apparatus, to Subcommittee LBI/36/4, Density me
4、asuring instruments. A list of organizations represented on this subcommittee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard ca
5、nnot confer immunity from legal obligations.Amendments/corrigenda issued since publication Date Comments Ma 2009 Implementation of ISO corrigendum December 2008 ISBN 978 0 580 67108 1 AC 1 AC 1y 31EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 15212-1 March 1999 ICS 17.060 English version
6、Oscillation-type density meters Part 1: Laboratory instruments (ISO15212-1:1998) Densimtres oscillations Partie 1: Instruments de laboratoire (ISO 15212-1:1998) Dichtemegerte nach dem Schwingerprinzip Teil 1: Laborgerte (ISO15212-1:1998) This European Standard was approved by CEN on3March1999. CEN m
7、embers are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on applic
8、ation to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has th
9、e same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Commit
10、tee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1999 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 15212-1:1999 EENISO15212-1:1999
11、 BSI 03-2000 Foreword The text of the International Standard from Technical Committee ISO/TC 48 “Laboratory glassware and related apparatus” of the International Organization for Standardization (ISO) has been taken over as an European Standard by Technical Committee CEN/TC332 “Laboratory equipment”
12、, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September1999, and conflicting national standards shall be withdrawn at the latest by September1999. Acco
13、rding to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portuga
14、l, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of the International Standard ISO15212-1:1998 has been approved by CEN as a European Standard without any modification. NOTENormative references to International Standards are listed inAnnex ZA (normative).iENISO15212-
15、1:1999 ii BSI 03-2000 Contents Page 1 Scope 1 2 Normative references 1 3 Definitions 1 4 Principle and functional units 1 4.1 Measuring principle 1 4.2 Functional units 1 5 Density sensor 2 5.1 Sensor material 2 5.2 Sensor design 2 6 Requirements and tests 2 6.1 Oscillation system 2 6.2 Temperature
16、control and measurement 3 6.3 Displays 4 6.4 Auxiliary units and data transfer 5 6.5 Safety requirements 5 6.6 Electromagnetic compatibility 5 7 Adjustment 5 8 Calibration 5 8.1 Density reference liquids 5 8.2 Particular density reference liquids 6 8.3 Calibration requirements 6 8.4 Calibration proc
17、edure 6 9 Density meter accuracy 6 10 Manual 7 11 Marking 7 Annex A (normative) Density and compressibility of pure water 8 Annex B (normative) Density of moist air 12 Annex C (informative) Bibliography 14 Annex ZA (normative) Normative references to international publications with their relevant Eu
18、ropean publications Inside back cover Figure 1 Functional units of a density meter 3 Table 1 Resolution and maximum permissible errors 5 Table A.1 Density wof pure water as function of the temperature t 90according to the international temperature scale from 1990 8 Table A.2 Isothermal compressibili
19、ty k wof pure water as function of the temperature t 90according to the international temperature scale from 1990 11 Table B.1 Densities of air at a relative air humidity of 50% as a function of temperature t 90and air pressure p 12 Table B.2 Correction values for the air densities in Table B.1 at d
20、ifferent temperatures and air humidities 13 Descriptors: laboratory equipment, measuring instruments, densitometers, specifications, metrological characteristics, performance, tests, performance tests, calibration, accuracy, marking.ENISO15212-1:1999 BSI 03-2000 1 1 Scope This part of ISO15212 speci
21、fies metrological and other requirements for oscillation-type density meters which are used in laboratories for all kinds of homogeneous 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 mor
22、e complex measuring equipment supplying additional test parameters of the sample. This part of ISO15212 does not describe the 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 s
23、uch as ISO or responsible government agencies. This part of ISO15212 does not define an instrument specification for any particular application. For this information reference should be made to the relevant standard covering the method of use. This part of ISO15212 is addressed to manufacturers of d
24、ensity meters and to bodies testing and certifying the conformity of density meters. In addition, this part of ISO15212 gives recommendations for adjustment and calibration of density meters by the user. 2 Normative references The following standards contain provisions which, through reference in th
25、is text, constitute provisions of this part of ISO15212. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO15212 are encouraged to investigate the possibility of applying the most recent editions o
26、f the standards indicated below. Members of IECandISO maintain registers of currently valid International Standards. ISO 3585:1998, Borosilicate glass 3.3 Properties. ISO 3696:1987, Water for analytical laboratory use Specification and test methods. IEC 61010-1:2001, Safety requirements for electric
27、al equipment for measurement, control and laboratory use Part 1: General requirements. IEC 61326-1:2005, Electrical equipment for measurement, control and laboratory use EMC requirements Part 1: General requirements. 3 Definitions For the purposes of this part of ISO 15212, the following definitions
28、 apply. NOTE The definitions and terms used are in agreement with the 1993 version of the International vocabulary of basic andgeneral terms in . 3.1 adjustment (of a density meter) operation of bringing the instrument to a state of performance suitable for its use, by setting or adjusting the densi
29、ty instrument constants NOTEBy adjustment, systematic measuring deviations are removed to an extent which is necessary for the provided application. Adjustment demands an intervention which permanently modifies the instrument. 3.2 calibration (of a density meter) set of operations that establishes t
30、he relationship between the reference density of standards and the corresponding density reading of the instrument NOTEBy calibration, no intervention is made which permanently modifies, for example, the instrument constants set during the adjustment procedure. 3.3 parasitic resonant points (of a de
31、nsity meter) those oscillation frequencies 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 mec
32、hanically induced oscillating systems, 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 samp
33、le density from the oscillation frequency or oscillation period. 4.2 Functional units Oscillation-type density meters shall consist of the following functional units: a) a density sensor capable of either being filled with the sample or of being immersed in it; b) a device to excite and control sens
34、or oscillation; c) a device to determine and display the density and the oscillation frequency or period; AC 1 AC 1 AC 1 AC 1 metrologyENISO15212-1:1999 2 BSI 03-2000 d) a device to determine and display the sample temperature for which the measured density is valid; e) a system to detect and displa
35、y malfunctions and operator errors. The functional unitsa) toc) are designated as the oscillation system. In addition, oscillation-type density meters can incorporate the following functional units: f) a unit for controlling the temperature of the sample and density sensor; g) sampling devices; h) s
36、ensor cleaning devices. All functional unitsa) toh) can be integrated into a single instrument or can be separate units. 5 Density sensor 5.1 Sensor material Density sensor materials can be, for example, borosilicate glass3.3 in accordance with ISO3585, metal, metal alloys or plastics. The material
37、is considered to be suitable if it shows in resistance tables the highest 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
38、 practical data available, the resistance of the sensor material should be 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 0,01% of the test-piece mass. b) Immerse the test piece in the fluid to be
39、 measured with the sensor, under the intended measuring conditions, e.g.temperature and pressure. c) After 12h remove, clean, dry and weigh the test piece. 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%. 5.2 Sensor
40、design Density sensors can be designed as straight, U-formed or omega-formed tubes. Other designs are tuning-forks, cylinders, bells or membranes. All designs which conform to the functional principle in accordance with4.1 can be constructed. 6.1 Oscillation system 6.1.1 Drift 6.1.1.1 Within24h, the
41、 drift of the displayed density % 24at a constant temperature of20 C shall not exceed1% of the maximum permissible error specified by the manufacturer of the instrument. If the density meter is not designed for a measuring temperature of20 C, the drift at the mean measuring temperature of the densit
42、y meter shall not exceed5% of the specified maximum permissible error. 6.1.1.2 Switch on the instrument and allow the temperature to equilibrate for24h. Adjust the instrument (see clause7) in accordance with the manufacturers instructions. Fill the instrument three times and measure the density of w
43、ater of Grade2 in accordance with ISO3696 at (20 0,1) C. Record the mean value of the threefold measurement 1 . Repeat the measurement (without a new adjustment) and repeat the mean value calculation 2after a minimum of10 days. The instrument and thermostating device shall be in operation during the
44、 whole test procedure. To calculate the drift, use the following equation: % 24= where %t is the difference in days between the two threefold measurements. If the density meter is not designed for a measuring temperature of20 C, testing shall be performed at the mean measuring temperature of the den
45、sity meter. 6.1.2 Effect of sample viscosity 6.1.2.1 The oscillation system shall be constructed in such a way that the maximum permissible errors conform to the requirements of clause9 when measuring samples of different viscosities and, where appropriate, with different sound velocities. 6.1.2.2 U
46、se Newtonian liquids of known densities and viscosities as well as, where appropriate, known 2 1 t -When the density meter is required for use ina country which has adopted a standard referencetemperature of 27 C (the alternative recommendedfor tropical use), this figure shall be substitutedfor20 C
47、and all temperatures representingdifferences in temperature compared to 20 Cshall bereplaced by corresponding temperatures,e.g., in 6.1.3.2, 30 C shall be replaced by 37 C.6 Requirements and tests All the tests of Clause 6 are intended to betype tests and to be performed at a measurement temperature
48、 of 20 C if not otherwise specified inthe text. AC 1 AC 1ENISO15212-1:1999 BSI 03-2000 3 6.1.3 Deviation between sample and sensor temperatures 6.1.3.1 The oscillation system shall be constructed and built in such a way that the deviation between sample temperature and sensor temperature at the mome
49、nt of display of the result does not exceed the values given in6.2. 6.1.3.2 Check the displayed density of the instrument over a defined time period. For this switch on the instrument and set the measurement temperature to20 C; attemperate the instrument for24h; precondition to30 C a reference liquid with high thermal density dependency; fill the density sensor with the preconditioned reference liquid. The first density value displayed by the instrument as valid or read from the instr
