1、BRITISH STANDARD BS EN ISO 15212-2:2002 Oscillation-type density meters Part 2: Process instruments for homogenous liquids ICS 17.060 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Incorporating corrigenda May 2002 and December 2008BS EN ISO 15212-2:2002 This British Standard
2、, was published under the authority of the Standards Policy and Strategy Committee on 26 April 2002 National foreword This British Standard is the UK implemen tion of EN ISO 15212-2:2002. It is identical with ISO15212-2:2002, incorporating corrigendum December 2008. The start and finish of text intr
3、oduced or 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 to Technical Committee LBI/36/4, Density measuring instruments. A list of organizations represented on
4、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 cannot confer immunity from legal obligations.Amendments/corri
5、genda issued since publication AC 1 AC 1 Amd. No. Date Comments 13920 Corr. No.1 15 May 2002 Incorporating Annex ZA and correction to EN ISO foreword Implementation of ISO corrigendum December 2008 BSI 2009 ISBN 978 0 580 67109 8 31 May 2009 aEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM ENISO15212
6、2 March2002 ICS17.060 Englishversion OscillationtypedensitymetersPart2:Processinstrumentsfor homogeneousliquids(ISO152122:2002) DensimtresoscillationPartie2:Instrumentsindustriels pourliquideshomognes(ISO152122:2002) DichtemessgertenachdemSchwingerprinzipTeil2: ProzessgertefrhomogeneFlssigkeiten(ISO
7、15212 2:2002) ThisEuropeanStandardwasapprovedbyCENon1March2002. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEuropean Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcerningsuchnational sta
8、ndardsmaybeobtainedonapplicationtotheManagementCentreortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytranslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusastheofficia
9、l versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROP
10、ISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2002CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.ENISO152122:2002EINESO51212:2002(2E) 2 CORRECTED20020417 Foreword Thisdocument(ISO152122:2002)hasbeenpreparedbyTechnicalCommittee
11、ISO/TC48 “Laboratoryglasswareandrelatedapparatus“incollaborationwithTechnicalCommittee CEN/TC332“Laboratoryequipment“,thesecretariatofwhichisheldbyDIN. ThisEuropeanStandardshallbegiventhestatusofanationalstandard,eitherbypublication ofanidenticaltextorbyendorsement,atthelatestbySeptember2002,andconf
12、licting nationalstandardsshallbewithdrawnatthelatestbySeptember2002. AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsof thefollowingcountriesareboundtoimplementthisEuropeanStandard:Austria,Belgium, CzechRepublic,Denmark,Finland,France,Germany,Greece,Iceland,Ireland,Ital
13、y, Luxembourg,Malta,Netherlands,Norway,Portugal,Spain,Sweden,Switzerlandandthe UnitedKingdom. Endorsementnotice ThetextoftheInternationalStandardISO152122:2002hasbeenapprovedbyCENasa EuropeanStandardwithoutanymodifications. NOTENormativereferencestoInternationalStandardsarelistedinannexZA(normative)
14、. 4egaP ENISO152122:2002 BS EN ISO 15212-2:2002 iii Contents Page 1 Scope . 1 2 Normative references . 1 3 Terms and definitions 2 4 Principle and functional units 2 4.1 Measuring principle . 2 4.2 Functional units . 2 5 Density sensor 4 5.1 Sensor material . 4 5.2 Sensor design 4 6 Requirements and
15、 tests 4 6.1 General 4 6.2 Density measuring transducer . 4 6.3 Liquid temperature measurement 6 6.4 Display and output of results . 7 6.5 Auxiliary units and data transfer 7 6.6 Safety requirements 8 6.7 Electromagnetic compatibility 8 7 Preadjustment and adjustment . 8 7.1 Preadjustment of process
16、 density meters . 8 7.2 Preadjustment of density measuring transducers . 8 7.3 Adjustment of installed density measuring transducers 8 7.4 Adjustment of processing units 8 8 Calibration 9 8.1 Laboratory calibration 9 8.2 In-situ calibration . 11 9 Process density meter accuracy . 13 9.1 Accuracy req
17、uirements 13 9.2 Laboratory conformity test . 13 9.3 In-situ tests 14 9.4 Test procedure and conformity assessment 14 10 Installation 15 11 Operating manual . 15 12 Marking . 16 ENISO152122:2002 BS EN ISO 15212-2:2002 v Introduction Density values of pure water at different temperatures and informat
18、ion on how to calculate the density values at different pressures can be found in ISO 15212-1:1998, annex A. ENISO152122:2002 BS EN ISO 15212-2:2002 1 Oscillation-type density meters Part 2: Process instruments for homogeneous liquids 1 Scope This part of ISO 15212 specifies metrological requirement
19、s, among others, for oscillation-type density meters as well as for functional units (see 4.2) of oscillation-type density meters, which are used in process for all kinds of homogeneous liquids. This includes liquified gases. Instructions and methods for installation, preadjustment, adjustment and c
20、alibration of process instruments are also given. The instruments are either integral systems or functional units, which can be combined into an integral measuring system. This part of ISO 15212 does not describe the method of use of process density meters for particular applications or products, e.
21、g. petroleum products or beverages. Such methods of use can be defined by relevant institutions such as ISO or responsible Government agencies. This part of ISO 15212 does not define an instrument specification for any particular application. For this information reference should be made to the rele
22、vant standard covering the method of use. This part of ISO 15212 is addressed to manufacturers of density meters and to bodies, testing and certifying the conformity of density meters. This part of ISO 15212 also gives recommendations for adjustment and calibration of process density meters. Oscilla
23、tion-type density meters used in laboratories are addressed in ISO 15212-1. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of ISO 15212. For dated references, subsequent amendments to, or revisions
24、 of, any of these publications do not apply. However, parties to agreements based on this part of ISO 15212 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative docum
25、ent referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 15212-1:1998, Oscillation-type density meters Part 1: Laboratory instruments IEC 61010-1, Safety requirements for electrical equipment for measurement, control and laboratory use Part 1
26、: General requirements ENISO152122:2002 IEC 61326-1, Electrical equipment for measurement, control and laboratory use EMC requirements Part 1: General requirements ISO/IEC Guide 98-3, Uncertainty of measurement Part 3: Guide to the expression of uncertainty in measurement (GUM:1995) AC 1 AC 1 BS EN
27、ISO 15212-2:20022 3 Terms and definitions For the purposes of this part of ISO 15212, the terms and definitions given in ISO 15212-1 and the following apply. 3.1 preadjustment process density meter adjustment performed in a laboratory environment before installation NOTE Adjustment, see 3.1 of ISO 1
28、5212-1:1998. 3.2 laboratory calibration process density meter calibration for the intended entire working range of the instrument performed in a laboratory environment before installation NOTE Calibration, see 3.2 of ISO 15212-1:1998. 3.3 in-situ calibration process density meter calibration of the
29、installed instrument for its actual working conditions in a process environment 4 Principle and functional units 4.1 Measuring principle The sensors used in density meters are electrically or mechanically induced oscillating systems, whose oscillation frequencies or periods are a function of the liq
30、uid density. Depending on the sensor design, the liquid can either flow through the sensor or the sensor can be immersed in the liquid. Instrument constants of the adjusted density meter are used to calculate the sample density from the oscillation frequency or oscillation period and from associated
31、 measurements, e.g. temperature or pressure. 4.2 Functional units Oscillation-type process density meters shall consist of the following functional units: a) a density sensor through which the liquid flows or which is immersed in the liquid; b) a device to determine the density sensor temperature; c
32、) a device to condition and/or preamplify the density sensor signal; d) a device to condition and/or preamplify the temperature sensor signal; e) a unit for signal processing, output of results and functional monitoring. Optional functional units of process density meters may be: f) a temperature tr
33、ansducer to measure the liquid temperature (see item 6 in Figure 1); g) a pressure transducer to measure the liquid pressure (see item 7 in Figure 1). The functional units a) to d) are often referred to as density measuring transducer (see item 8 in Figure 1). The unit e) can be referred to as proce
34、ssing or indicating unit (see item 5 in Figure 1) and may accept additional signals or process parameters, e.g. from a flow meter. The functional units, items 5 and 8 in Figure 1, can be integrated into a single instrument or can be separate units. ENISO152122:2002 BS EN ISO 15212-2:2002 3 Key 1 Den
35、sity sensor see 4.2 a) 2 Temperature sensor see 4.2 b) 3 Density sensor signal preamplification see 4.2 c) 4 Temperature sensor signal preamplification see 4.2 d) 5 Processing or indicating unit see 4.2 e) 6 Temperature transducer see 4.2 f) 7 Pressure transducer see 4.2 g) 8 Density measuring trans
36、ducer 9 Liquid to be measured 10 Output (display, printer, interface) Figure 1 Functional units of a process density meter ENISO152122:2002 BS EN ISO 15212-2:20024 5 Density sensor 5.1 Sensor material Density sensor materials can be, for example, metal, metal alloys, coated metals or glass. The mate
37、rial is considered to be suitable if it is compatible with the process liquids to be measured at the process conditions and with the cleaning agents to be used in the density meter. Erosion, abrasion as well as special forms of corrosion shall be considered in this respect since they have an impact
38、on the accuracy of the instrument. The manufacturer shall provide certificates about the sensor material on request. 5.2 Sensor 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
39、 with the functional principle in accordance with 4.1 can be constructed. 6 Requirements and tests 6.1 General 6.2 Density measuring transducer 6.2.1 Drift 6.2.1.1 Within 30 days, the drift of the measured density at a temperature of , at a pressure of to 1)( to ) and at a typical flow rate specifie
40、d in the manual shall not exceed of the maximum permissible error specified by the manufacturer for the instrument. If the working range of the density meter does not include the above mentioned conditions, the drift at the typical measuring conditions of the density meter shall not exceed of the sp
41、ecified maximum permissible error. 6.2.1.2 The test for the drift determination shall be performed as follows: install the instrument, preadjusted by the manufacturer, to a liquid circulation system; suited liquids can be for example water or mineral oil; switch on the instrument and attemper it for
42、 ; circulate the liquid through the instrument and record the density at least three times at within ;1) . 30 20 C 0,1 MPa 0,2 MPa 1 bar 2 bar 20 % 1 bar= 10 5 N/m 2 = 0,1 MPa 40 % 24 h (20 0,1) C 30 min ENISO152122:2002 All the tests of Clause 6 are intended to be type tests and to be performed at
43、a measurement temperatureof 20 C if not otherwise specified in the text. When the density meter is required for use in a country which has adopted a standard reference temperatureof 27 C (the alternative recommended for tropical use), this figure shall be substituted for 20 C and alltemperatures rep
44、resenting differences in temperature compared to 20 C shall be replaced by correspondingtemperatures, e.g., in 6.2.1.2, (10 1) C shall be replaced by (17 1) C and (30 1) C by (37 1) C. AC 1 AC 1 BS EN ISO 15212-2:2002 5 Instrument, liquid circulation and thermostating device shall be in operation du
45、ring the whole test. During the minimum time period of 30 days between the two density measurements, the instrument shall be run at least 2 days at a temperature of and another 2 days at a temperature of . To calculate the drift, , use the following equation: (1) where is the difference in days betw
46、een the two threefold measurements. If the density measuring transducer is not designed for a measuring temperature of , testing shall be performed at the mean measuring temperature of the density measuring transducer. The increased and decreased temperature between the two density measurements shal
47、l be and from this mean measuring temperature. 6.2.2 Effect of liquid properties 6.2.2.1 The density measuring transducer shall be constructed in such a way, that the maximum permissible errors are in accordance with the requirements given in 9.1 when measuring liquids with different sound velocitie
48、s and, where appropriate, having different viscosities. 6.2.2.2 For testing, use Newtonian liquids with known densities and sound velocities as well as, where appropriate, known viscosities. They shall cover the intended application range of the density meter specified by the manufacturer with regard to sound velocity and viscosity. Testing shall be performed in accordance with 9.2. 6.2.3 Deviation between li
