1、May 2015Translation by DIN-Sprachendienst.English price group 11No 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 for German Standards (DIN-Normen).ICS 23.
2、160!%Ba“2316288www.din.deDDIN ISO 3567Vacuum gauges Calibration by direct comparison with a reference gauge(ISO 3567:2011),English translation of DIN ISO 3567:2015-05Vakuummeter Kalibrieren von Vakuummetern durch direkten Vergleich mit einem Bezugsnormal(ISO 3567:2011),Englische bersetzung von DIN I
3、SO 3567:2015-05Manomtres talonnage par comparaison directe avec un manomtre de rfrence (ISO 3567:2011),Traduction anglaise de DIN ISO 3567:2015-05SupersedesDIN 28418-1:1976-05, withdrawn2013-08,DIN 28418-2:1978-09, withdrawn2009-09 andDIN 28418-3:1980-08www.beuth.deIn case of doubt, the German-langu
4、age original shall be considered authoritative.Document comprises 19 pages04.15 DIN ISO 3567:2015-052A comma is used as the decimal marker. Contents Page National foreword .3 Introduction .5 1 Scope .6 2 Normative references .6 3 Terms and definitions 6 4 Symbols and abbreviated terms .8 5 General p
5、rinciple 9 6 Requirements 9 6.1 Design of calibration chamber 9 6.2 Plumbing of gauges to calibration chamber 10 6.3 Vacuum and gas inlet system . 11 6.4 Calibration gas 11 6.5 Thermometers and ambient conditions . 11 6.6 Reference gauge 12 7 Calibration 12 7.1 Procedure . 12 7.2 Evaluation of measu
6、rements 14 7.3 Measurement uncertainty . 14 8 Calibration certificate 15 Annex A (informative) Example of possible calibration system set-up 16 Annex B (informative) Problems in practice 17 Bibliography . 19 National foreword The text of this document (ISO 3567:2011) has been prepared by Technical C
7、ommittee ISO/TC 112 “Vacuum technology”, Working Group WG 2 “Vacuum instrumentation”. The responsible German body involved in its preparation was the DIN-Normenausschuss Maschinenbau (DIN Standards Committee Mechanical Engineer-ing), Working Committee NA 060-07-02 AA Vakuummessgerte of Section Vakuu
8、mtechnik. ISO 3567:2011 cancels and replaces ISO/TS 3567:2005. It replaces the standards DIN 28418-1 to DIN 28418-3 and differs from these in that numerous modifications have been made to reflect the state of the art, in addition to the following: The calibration chamber is to be chamber-symmetrical
9、 (6.1.b), and its volume is only to be 20 times (and not 50 times, as specified in the DIN Standards) the total volume of all the gauges and associated pipe work. The residual pressure now called the “base pressure” is not to go below 10 % (previously, 2 %) of the lowest calibration pressure so that
10、 ion gauges with sensitivities of up to 106Pa can also be calibrated without placing too strict requirements on the vacuum system. Requirements are now specified for the reference gauge. An entire subclause is dedicated to measurement uncertainty, subclause 7.3. Attention is drawn to the possibility
11、 that some of the elements of this document may be the subject of patent rights. DIN and/or DKE shall not be held responsible for identifying any or all such patent rights. For the International Standards referred to in this document there are no national standards available unless they have been pu
12、blished as DIN EN ISO or DIN ISO standards with the same number. The document corresponding to ISO/IEC Guide 98-3 is DIN V ENV 13005:1999-06, Guide to the expression of uncertainty in measurement. nderungen This standard differs from DIN 28418-1:1976-05, DIN 28418-2:1978-09 and DIN 28418-3:1980-08 a
13、s follows: a) the calibration chamber is to be chamber-symmetrical (6.1.b); b) the volume of the calibration chamber is only to be 20 times (and not 50 times, as specified in the DIN Standards) the total volume of all the gauges and associated pipe work; c) the residual pressure now called the “base
14、 pressure” is not to go below 10 % (previously, 2 %) of the lowest calibration pressure so that ion gauges with sensitivities of up to 106Pa can also be calibrated without placing too strict requirements on the vacuum system; d) requirements are now specified for the reference gauge; e) requirements
15、 are now specified for the measurement uncertainty of the method; f) an entire subclause is dedicated to measurement uncertainty, Subclause 7.3. Previous editions DIN 28418-1: 1976-05 DIN 28418-2: 1978-09 DIN 28418-3: 1980-08 DIN ISO 3567:2015-053 This page is intentionally blank DIN ISO 3567:2015-0
16、54Vacuum gauges Calibration by direct comparison with a reference gauge IntroductionThe purpose of this International Standard is to establish the physical, technical and metrological conditions necessary for adequately disseminating the pressure scale in the vacuum regime by calibration with a refe
17、rence gauge. It is assumed that the user will be familiar with the general procedures of vacuum generation and measurement in the vacuum ranges considered.DIN ISO 3567:2015-0551 ScopeThis International Standard specifies the physical, technical and metrological conditions to be fulfilled when calibr
18、ations of vacuum gauges are performed by direct comparison with a reference gauge. From the conditions described, the design of an apparatus that can perform vacuum gauge calibrations in an adequate manner can be deduced.The vacuum gauges to be calibrated can be of any kind. Many types of gauges con
19、sist of several parts. Typically, these are: gauge head, cable, operational device and signal read out. This entire set is considered as the unit that has to be calibrated. Whereas, if only the gauge head (i.e. the part of the vacuum gauge directly exposed to the vacuum) is calibrated, all set-ups a
20、nd conditions would have to be recorded such that the user of the calibrated gauge head would be able to perform the measurements in the same manner as during the calibration.The reference gauge is either a calibrated gauge, traceable to a vacuum primary or national standard (normal case), with a ca
21、libration certificate according to ISO/IEC 17025, or an absolute measuring instrument (rare case), traceable to the SI units and to which a measurement uncertainty can be attributed.This International Standard does not give guidance on how to treat special types of vacuum gauges, be they reference s
22、tandards or units under calibration; it is intended that such guidance be given in other International Standards.The pressure range for calibrations treated in this International Standard depends on the realized design of the calibration apparatus and on the type of reference gauge. The range varies
23、 in its limits from 106Pa to 110 kPa.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments)
24、 applies.ISO/IEC Guide 98-3, Uncertainty of measurement Part 3: Guide to the expression of uncertainty in measurement (GUM:1995)ISO/IEC 17025:2005, General requirements for the competence of testing and calibration laboratories3 Terms and definitionsFor the purposes of this document, the following t
25、erms and definitions apply.3.1primary standardmeasurement standard established using a primary reference measurement procedure SOURCE: ISO/IEC Guide 99:2007, 5.4, modified3.2national standardmeasurement standard recognized by national authority to serve in a state or economy as the basis for assigni
26、ng quantity values to other measurement standards for the kind of quantity concernedSOURCE: ISO/IEC Guide 99:2007, 5.3DIN ISO 3567:2015-0563.3reference standardmeasurement standard designated for the calibration of other measurement standards for quantities of a given kind in a given organization or
27、 at a given locationSOURCE: ISO/IEC Guide 99:2007, 5.6NOTE In this International Standard, it is synonymous with reference gauge.3.4vacuum gaugeinstrument for measuring gas or vapour pressure that is less than the prevailing atmospheric pressureSOURCE: ISO 3529-3:1981, 3.1.2NOTE 1 Some types of vacu
28、um gauges commonly in use do not measure a pressure directly, but measure some other physical quantity which, under specific conditions, is related to pressure.NOTE 2 For terms and definitions of the various vacuum gauges in use, see ISO 3529-3.3.5gauge headpart of the gauge which contains the press
29、ure-sensitive element and which is directly connected to the vacuum system NOTE A gauge head comprising its operational device is usually called a transmitter.SOURCE: ISO 3529-3:1981, 3.1.2.1, modified3.6operational devicepart of a vacuum gauge that operates the gauge head and/or delivers the signal
30、 related to pressure3.7unit under calibrationUUCvacuum gauge to be calibrated3.8entrance flangeflange by which the unit under calibration or the reference gauge is connected to the calibration chamber3.9calibration chambervacuum chamber that serves as a common vacuum medium for the reference gauge a
31、nd unit under calibration3.10entrance mouthopening in the calibration chamber which leads to a unit under calibration, reference gauge or any other part of the calibration system3.11calibration gasgas species or mixture that is used to change the pressure in the calibration chamber3.12sorptiontaking
32、 up of a gas or vapour by a solid or liquid3.13desorptionliberation of gases or vapours sorbed by a materialDIN ISO 3567:2015-0573.14outgassing raterate at which molecules and atoms desorb from a material exposed to a vacuum3.15total pressurepsum of pressures of all the components of a gaseous mixtu
33、reNOTE A vacuum is usually measured as the absolute pressure of gas prevalent in an enclosed chamber, expressed in pascals (Pa) or millibars (mbar): 1 mbar = 100 Pa; 1 bar = 0,1 MPa = 105Pa; 1 MPa = 1 N/mm2.3.16residual pressurelowest pressure that can be reached in the calibration chamber, typicall
34、y after 24 h of pumpingNOTE The residual pressure depends, among others things, on the bake-out condition of the calibration chamber.3.17base pressurepressure in the calibration chamber that exists either before gas is admitted into the calibration chamber for calibration, or later, after the gas in
35、let valve has been turned off for some timeNOTE The base pressure can be higher than the residual pressure, but cannot be lower.4 Symbols and abbreviated termsD diameter of cylinder, expressed in millimetres (mm)e error of readingp total vacuum pressure, expressed in pascals (Pa) or millibar (mbar)p
36、0base pressure, expressed in pascals (Pa) or millibar (mbar)pcalcalibration pressure, expressed in pascals (Pa) or millibar (mbar)pindindicated pressure, expressed in pascals (Pa) or millibar (mbar)presresidual pressure, expressed in pascals (Pa) or millibar (mbar)Qoutoutgassing rate, expressed in p
37、ascal litres per second (Pa L/s), pascal cubic metres per second (Pa m3/s) or millibar litres per second (mbar L/s)qv,effeffective volume flow rate of the pump effective litres per second (L/s) or cubic metres per second (m3/s) volume flow rate into pumpS sensitivity (coefficient) (Pa1)u standard un
38、certaintyU expanded uncertaintyCF correction factorUUC unit under calibrationDIN ISO 3567:2015-0585 General principleThe UUC is connected to the same calibration chamber as the reference gauge.Calibration of a vacuum gauge the UUC by comparison with a reference gauge is done by exposing the entrance
39、 flange of the UUC and that of the reference gauge to the same density and velocity distribution of calibration gas molecules. The same density and velocity distribution of these molecules means the same pressure at the two locations, but not vice versa. Since there are many types of vacuum gauge th
40、at do not measure pressure but instead, for example, gas density or the impingement rate of gas molecules the above requisite is both necessary and more stringent than only calling for equal pressures at the two entrance flanges.The gas density (pressure) in the calibration chamber can be varied and
41、 the gauge readings of the UUC compared with the pressures indicated by the reference gauge.From this general principle, the requirements (see Clause 6) for the design of the calibration apparatus are deduced.6 Requirements6.1 Design of calibration chamberThe chamber shall be designed to ensure that
42、 the distribution of gas in the measuring volume is sufficiently uniform in space and stable in time.In addition, the material of the calibration chamber shall be chosen such that the residual pressure, pres, determined by the effective pumping speed, qv,eff(effective volume flow rate into pump), an
43、d the total outgassing rate in the calibration chamber, Qout(absence of leaks), is low enough to perform the calibrations, as expressed by Formula (1) (see also 6.3):pQqresoutv,eff= (1)In detail, the calibration chamber shall be designed and operated as follows. However, design criteria a) to e) may
44、 be disregarded when the minimum pressures to be realized in the vacuum chamber are larger than 100 Pa and only static pressures (see 7.1) are established. Independent of pressure, criteria b) to d) may be disregarded when only static pressures are established.a) The calibration chamber shall have a
45、 volume of at least 20 times the total volume of all the gauges and associated pipe work connecting the chamber and the gauges (e.g. elbows shall be considered as part of the gauge volume).b) The shape of the calibration chamber (see Figure 1) shall be cylinder-symmetrical to at least one axis. A sp
46、here is ideal, but two symmetrical domes, each a part of a sphere and attached to one another, or cylinders, are equally possible. Where a cylinder is used, its overall length shall be within one and two times its diameter, and domed ends are recommended.c) The centre of the cross-sectional area of
47、the pumping outlet and the gas inlet (if applicable) shall lie on the same cylindrical axis of symmetry of the calibration chamber. The gas inlet may be positioned between the pump outlet and pump system (see 6.3), in which case there is no need to have the gas inlet on the axis of symmetry.d) All e
48、ntrance mouths and their respective flanges to which either the UUCs or the reference gauges are to be connected shall be on a common equatorial plane, perpendicular to the cylindrical axis of symmetry chosen for the pumping outlet.Where a cylinder is used, it is recommended that this equatorial pla
49、ne separate the cylinder into two halves of equal length. Where a cylinder with a length of (3/2)D in relation to its diameter is used (suitable DIN ISO 3567:2015-059for pump speed measurements), the gauges may be placed at one third of the length (D/2) above the bottom flange.e) Temperature differences between arbitrary points across the calibration chamber shall be less than 1 K. Points closer than 5 cm from the entrance mouth to a heated vacuum gauge
