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1、BRITISH STANDARD BS ISO 11605:1995 Implementation of ISO 11605:1995 Paper and board Calibration of variable-area flowmeters ICS 85.060 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:23:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 11605:1995 This British Standard, having been prepa
2、red under the direction of the Sector Board for Materials and Chemicals, was published under the authority of the Standards Board and comes into effect on 15 August 1995 BSI 01-2000 The following BSI references relate to the work on this standard: Committee reference PAI/11 Draft for comment 93/3040
3、64 DC ISBN 0 580 24297 8 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee PAI/11, Methods for test for paper, board and pulp, upon which the following bodies were represented: British Carton Association British Fibreboard
4、Packaging Association British Printing Industries Association British Textile Confederation Envelope Makers and Manufacturing Stationers Association Her Majestys Stationery Office Institute of Paper Conservation Pira International Post Office The Paper Federation of Great Britain University of Manch
5、ester (Institute of Science and Technology) Coopted Members Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:23:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 11605:1995 BSI 01-2000i Contents Page Committees responsibleInside fr
6、ont cover National forewordii Forewordiii Text of ISO 116051 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:23:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 11605:1995 ii BSI 01-2000 National foreword This British Standard reproduces verbatim ISO 11605:1995 and implements it as the
7、 UK national standard. This British Standard is published under the direction of the Sector Board for Materials and Chemical whose Technical Committee PAI/11 has the responsibility to: aid enquirers to understand the text; present to the responsible international committee any enquiries on interpret
8、ation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. NOTEInternational and European Standards, as well as overseas standards, are available from Customer Services, BSI, 389 Chiswick High Road, London W4
9、 4AL. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comp
10、rises a front cover, an inside front cover, pages i and ii, the ISO title page, pages ii to iv, pages 1 to 4 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licens
11、ed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:23:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:23:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 11605:1995(E) ii BSI 01-2000 Contents Page Forewordiii 1Scope1 2Normative references1 3P
12、rinciple1 4Apparatus1 5Procedure1 6Calculation3 Annex A (informative) Compensation for the relative humidity of the air4 Annex B (informative) Bibliography4 Figure 1 Soap bubble meter2 Descriptors: Paper, paperboards, tests, determination, smoothness, roughness, gas permeability, test equipment, flo
13、wmeters, calibration. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:23:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 11605:1995(E) BSI 01-2000iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodie
14、s). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and n
15、on-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodie
16、s for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 11605 was prepared by Technical Committee ISO/TC 6, Paper, board and pulps, Subcommittee SC 2, Test methods and quality specifications for paper a
17、nd board. Annex A and Annex B of this International Standard are for information only. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:23:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:23:52 GMT+00:00 2006, Uncontrolled Copy
18、, (c) BSI ISO 11605:1995(E) BSI 01-20001 1 Scope This International Standard specifies a method for the calibration of variable-area flowmeters as used in instruments for the determination of air permeance and the roughness/smoothness of paper and board. Other meters, such as an electronic mass flow
19、meter may be used, provided their accuracy is at least as good as that of the specified method. NOTE 1This procedure may also be used for calibrating the capillary tubes used to check the Bendtsen apparatus. 2 Normative references The following standards contain provisions which, through reference i
20、n this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most r
21、ecent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 187:1990, Paper, board and pulps Standard atmosphere for conditioning and testing and procedure for monitoring the atmosphere and conditioning of samples. ISO 56
22、36-3:1992, Paper and board Determination of air permeance (medium range) Part 3: Bendtsen method. ISO 5636-4:1986, Paper and board Determination of air permeance (medium range) Part 4: Sheffield method. ISO 8791-2:1990, Paper and board Determination of roughness/smoothness (air leak methods) Part 2:
23、 Bendtsen method. ISO 8791-3:1990, Paper and board Determination of roughness/smoothness (air leak methods) Part 3: Sheffield method. ISO 8791-4:1992, Paper and board Determination of roughness/smoothness (air leak methods) Part 4: Print-surf method. ISO 11004:1992, Paper and board Determination of
24、air permeance Low range. 3 Principle A soap bubble, introduced into an air flow from the variable-area flowmeter under test, is timed between two marks in a volumeter representing an accurately known volume and the actual air flow is calculated. This is repeated at other air flows until the flowmete
25、r range has been covered. 4 Apparatus 4.1 Soap bubble meter (see Figure 1) consisting of: glass flask or bottle, of capacity 1 litre; volumeter, calibrated at graduation marks appropriate to the flowmeter to be calibrated, for example, marks approximating 100 ml, 250 ml, 500 ml, 1 000 ml, 1 500 ml a
26、nd 2 000 ml. The different ranges may be achieved with replaceable volumeters (additional designs are discussed by Gooderham 1); needle valve1); glass and rubber tubing of as large an internal diameter and as short as is practicable to minimize pressure drop. 4.2 Stopwatch, capable of being read to
27、0,1 s. 4.3 Soap solution, comprising, for example, 3 % to 5 % liquid detergent in distilled water. 5 Procedure 5.1 General Carry out the calibration procedure in the same atmosphere as normally used for testing (see ISO 187). 5.2 Bendtsen apparatus (for description of the apparatus, see ISO 5636-3 o
28、r ISO 8791-2) 5.2.1 Disconnect the measuring head from the downstream end of the rubber or plastics tubing and connect in its place the soap bubble meter at A (see note 2). Start the air flow, place the manostat which corresponds to a pressure of 1,47 kPa on the shaft and start it spinning. Set the
29、valves to deliver to the soap bubble meter through the flowmeter being calibrated. NOTE 2The internal diameters of the tubing connecting the flowmeter to the air permeance measuring head or the roughness head are different. Consequently, the pressure drop and therefore the calibration can change bet
30、ween these configurations. Therefore, it is advisable to verify periodically that both calibrations are within 5 % of the true air flow (see 6.1). 5.2.2 Adjust the needle valve C to give a conveniently measurable air flow and ensure that the flowrate remains constant. Rapidly squeeze the rubber bulb
31、 E at the bottom of the volumeter D so that a soap bubble enters the volumeter tube. Note the time, in seconds to the nearest 0,1 s, for it to move between marks representing a known volume, and record the flowmeter reading. The volumeter range should be chosen so that time measurements are in exces
32、s of 30 s. Repeat the procedure at about six air flows distributed over the upper 80 % of the flowmeter working range. 1) The needle valve has to be removed for calibration of the Print-surf apparatus. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:23:52 GMT+00:00 2006, Uncontrolled Copy,
33、 (c) BSI ISO 11605:1995(E) 2 BSI 01-2000 NOTE 3Squeezing the bulb creates a pressure fluctuation which may take the manostat several seconds to stabilize. This can cause the indicated flow to be seriously in error and it is therefore important to allow the flowmeter float to stabilize before the soa
34、p film passes the lower timing mark. NOTE 4At air flows above 1 200 ml/min, the pressure drop in the system is substantial and to ensure reproducibility of results it is necessary to ensure that the length and diameter of the tubing used in calibration to connect the flowmeter outlet to A are the sa
35、me as those used in normal testing. 5.3 Sheffield apparatus Conduct the internal calibration of the flowmeter as described in ISO 5636-4 or ISO 8791-3. Disconnect the measuring head from the downstream end of the rubber or plastics tubing and connect in its place the soap bubble meter at A. Set the
36、valves to deliver through the flowmeter being calibrated and continue the procedure as described in 5.2.2 (see also notes 3 and 4). 5.4 Print-surf apparatus (non-impedance type) Remove needle valve C and connect the inlet (A) of the soap bubble meter to the outlet of the flowmeter being calibrated.
37、Operate the instrument according to the procedure described in subclauses 9.1 to 9.6.1 inclusive of ISO 8791-4:1992, using a test piece of suitable roughness (see note 4). Rapidly squeeze the rubber bulb E at the bottom of the volumeter D so that a soap bubble enters the volumeter tube. Note the tim
38、e, in seconds to the nearest 0,1 s, for the bubble to move between marks representing a known volume, and record the flowmeter reading. Repeat the procedure using test pieces of appropriate roughness to provide about six air flows distributed over the upper 80 % of the flowmeter working range. NOTE
39、5Some paper test pieces may not give stable scale readings during the calibration procedure due to the effect of moisture change during the test. Do not use material which behaves in this way. Materials other than paper may be used, providing they give readings at appropriate intervals over the rang
40、e of the flowmeter being calibrated. 1) Removed for calibration of Print-surf apparatus. Figure 1 Soap bubble meter Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:23:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 11605:1995(E) BSI 01-20003 5.5 Low-permeance apparatus (see ISO 11004) Co
41、nnect the upper part (open end) of the largest flowmeter to the soap bubble meter at A. Start the compressor and continue the procedure as described in 5.2.2 (see also notes 3 and 4). 6 Calculation 6.1 Bendtsen apparatus Calculate the true air flow, in millilitres per minute, from each measured time
42、 and volume and check that the flowmeter reading is within 5 % of this flow. If not, examine the flowmeter tubes and rotor for dirt and/or damage and replace if necessary. As a temporary measure, a calibration graph may be constructed. NOTE 6If extreme accuracy is required, it may be necessary to co
43、rrect for temperature, pressure and the water vapour picked up from the soap solution, but the precision of the respective test method in other respects does not warrant the application of this correction. 6.2 Sheffield apparatus Calculate the true air flow, in millilitres per minute, from each meas
44、ured time and volume and construct a calibration graph for each flowmeter. The three graphs for a single instrument should constitute a straight line and if they do not there is a defect in the flowmeter tubes or the orifice manifold. The equation to the graph is of the form air flow (ml/min) = A +
45、BX where (See also note 6.) 6.3 Print-surf apparatus Calculate the true air flow, in cubic metres per second, for each measured time and volume and convert each air flow to roughness R, in micrometres, by means of the equation where Compare the calculated values with the actual scale readings. If th
46、e instrument reading is more than 0,05 4m from the calculated value at any point, construct a calibration graph. NOTE 7For very accurate calibration, it is desirable to allow for the water vapour picked up from the soap solution. A means of carrying out this determination is given, for information,
47、in Annex A. 6.4 Low-permeance apparatus Calculate the true air flow, in millilitres per second, from each measured time and volume and compare with the flowmeter reading. If the flowmeter readings differ from the flowrate by more than 2 % of the full scale value, examine the flowmeter tubes and roto
48、rs for dirt and/or damage and replace if necessary. As a temporary measure, a correction chart of air flow versus flowmeter readings may be constructed. Ais a constant (usually between 500 and + 150); Bis a constant (usually between 8 and 9,5); Xis the scale reading, in Sheffield units. is the visco
49、sity of air at room temperature, in pascal seconds; bis the width of the metering land, in metres; qVis the true air flow in unit time, in cubic metres per second; lis the effective length of the metering land, in metres; %pis the pressure difference across the metering land, in pascals. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:23:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 11605:1995(E) 4 BSI 01-2000 Annex A (informative) Compensation for the relative humidity of the air In the course of carrying o
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