1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58reflected light using Equivalent Black Area (EBA) methodICS 85.040Pulps Estimation of dirt and shiv
2、es Part 4: Instrumental inspection by BRITISH STANDARDBS ISO 5350-4:2006BS ISO 5350-4:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 October 2006 BSI 2006ISBN 0 580 49418 7Amendments issued since publicationAmd. No. Date Commentscontr
3、act. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.National forewordThis British Standard was published by BSI. It is the UK implementation of ISO 5350-4:2006. It supersedes BS ISO 15319:1999 which is withdrawn.The
4、UK participation in its preparation was entrusted to Technical Committee PAI/11, Methods of test for paper, board and pulps.A list of organizations represented on PAI/11 can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a INTERNA
5、TIONALSTANDARDISO5350-4First edition2006-09-01Reference numberISO 5350-4:2006(E)Pulps Estimation of dirt and shives Part 4:Instrumental inspection by reflected light using Equivalent Black Area (EBA) methodPtes Estimation des impurets et bchettes Partie 4: Examen instrumental par lumire rflchie util
6、isant la mthode de la surface noire quivalente (mthode EBA)BS ISO 5350-4:2006iiiiiContents Page1 Scope 12 Normative references 13 Terms and definitions 14 Principle 25 Apparatus . 26 Sampling . 36.1 General . 36.2 Pulp sheets 36.3 Slush or flash-dried pulp . 37 Procedure . 37.1 General . 37.2 Calibr
7、ation 37.3 Examination . 48 Expression of results 59 Precision . 59.1 General . 59.2 Repeatability 69.3 Reproducibility 610 Test report 6Annex A (normative) Equivalent Black Area (EBA) calculations . 7Annex B (normative) Calibration-plate information 9Bibliography . 10BS ISO 5350-4:2006ivForewordISO
8、 (the International Organization for Standardization) is a worldwide federation of national standards bodies(ISO member bodies). The work of preparing International Standards is normally carried out through ISOtechnical committees. Each member body interested in a subject for which a technical commi
9、ttee has beenestablished has the right to be represented on that committee. International organizations, governmental andnon-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the InternationalElectrotechnical Commission (IEC) on all matters of electrotechni
10、cal standardization.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft International Standardsadopted by the technical committees are circulated to the member bodi
11、es for voting. Publication as anInternational Standard requires approval by at least 75 % of the member bodies casting a vote.Attention is drawn to the possibility that some of the elements of this document may be the subject of patentrights. ISO shall not be held responsible for identifying any or
12、all such patent rights.ISO 5350-4 was prepared by Technical Committee ISO/TC 6, Paper, board and pulps, Subcommittee SC 5,Test methods and quality specifications for pulps.ISO 5350-4 cancels and replaces ISO 15319:1999, Recycled pulps Estimation of visible contraries byinstrumental means using refle
13、cted light, because ISO 5350-4 is also intended for recycled pulp.ISO 5350 consists of the following parts, under the general title Pulps Estimation of dirt and shives: Part 1: Inspection of laboratory sheets by transmitted light Part 2: Inspection of mill sheeted pulp by transmitted light Part 3: V
14、isual inspection by reflected light using Equivalent Black Area (EBA) method Part 4: Instrumental inspection by reflected light using Equivalent Black Area (EBA) methodBS ISO 5350-4:2006vIntroductionThe level of visible dirt present in pulp can impact its usefulness in a specific end-use application
15、. In suchcases, the presence of visible dirt specks which are high in number, easily noticed in visual examination, orboth, may detract more from the apparent usefulness of the paper material than does a lower number ofspecks, or specks which are less easily noticed by the eye. Both the number of di
16、rt specks and their visualimpact may be important. For someone controlling or monitoring the paper-making process, the absolutephysical area of dirt, or the number of dirt specks present in an inspection area, may be of the greatestimportance. For the end user of the paper material, the overall visu
17、al impression may be the critical parameter.This part of ISO 5350 is complementary to ISO 5350-3, which concerns visual inspection of mill pulp byreflected light using the Equivalent Black Area (EBA) method.ISO 5350-1 and ISO 5350-2 are based on visual inspection by transmitted light.BS ISO 5350-4:2
18、006blank1Pulps Estimation of dirt and shives Part 4:Instrumental inspection by reflected light using Equivalent Black Area (EBA) method1ScopeThis part of ISO 5350 specifies a method using instrumental inspection by reflected light for the estimation ofvisible dirt and shives in pulp manufactured in
19、sheets, in terms of Equivalent Black Area (EBA) of dirt speckswithin the physical area range of to . Using the algorithm prescribed in this part of ISO 5350,the maximum dirt size is limited to . Extension to other speck sizes (for example, those greater thanin physical area) may require changes in e
20、quipment, calculation procedures, or both, and is notcovered in this part of ISO 5350. This part of ISO 5350 cannot be used for physical area measurements, sinceit may not correctly measure the dirt specks for that mode of measurement.The specimen to be evaluated should have a brightness, as determi
21、ned by ISO 3688, of or greater. It maybe necessary to reform some pulp sheets into laboratory sheets, if the surface is too rough or textured.This part of ISO 5350 is also intended for recycled pulp.2 Normative referencesThe following referenced documents are indispensable for the application of thi
22、s document. For datedreferences, only the edition cited applies. For undated references, the latest edition of the referenced document(including any amendments) applies.ISO 3688, Pulps Preparation of laboratory sheets for the measurement of diffuse blue reflectance factor (ISObrightness)ISO 5269-1,
23、Pulps Preparation of laboratory sheets for physical testing Part 1: Conventional sheet-formermethodISO 5269-2, Pulps Preparation of laboratory sheets for physical testing Part 2: Rapid-Kthen methodISO 7213, Pulps Sampling for testing3 Terms and definitionsFor the purposes of this document, the follo
24、wing terms and definitions apply.3.1 sheetsheet of pulp taken from a bale, or a part of a roll of pulp3.2 test piecearea taken for inspection0,02 mm23,0 mm23,0 mm23,0 mm230 %BS ISO 5350-4:200623.3 laboratory sheetsheet formed from disintegrated pulp3.4 contrary in pulpany unwanted particle, of speci
25、fied minimum size and having a contrasting colour with respect to thesurrounding area of the sheet, according to the comparison chart given in Annex B3.5 dirtany non-fibrous contrary3.6 shivesliver of wood, or fibre bundle3.7 equivalent black area (EBA)area of one of the round black spots (a value o
26、f ) that has the same apparent area when examinedvisually upon its white background (a value of ) as does the dirt speck when examined visually uponthe particular sheet in or upon which it is embeddedNOTE 1 A larger “grey” dirt speck has the same visual impact as a smaller “black” one when viewed on
27、 the same sheet andunder the same conditions.NOTE 2 The Equivalent Black Area (EBA) of a dirt speck determined visually is generally less than its physical area. TheEBA approaches the physical area only as the speck becomes large.4PrincipleThe test pieces to be examined are inspected on both sides w
28、ith reflected light. The area of all contraries largerthan a specified value and showing contrast, with respect to the surrounding area of the sheet are estimated.The total Equivalent Black Areas (EBA) of the contraries are calculated, and the total number and the totalEquivalent Black Area (EBA) of
29、 dirt and shives are reported as the number of contraries per square metre andas square millimetre per square metre (number of contraries/m2and mm2/m2), respectively.5 ApparatusAn automatic device for counting of contraries shall include the following parts.5.1 Detector, of the densitometric type, w
30、ith at least 256 grey levels (G.L.) of sensitivity with the physical pixelresolution having an effective area of or less. The detector shall view the specimen normal to itssurface. The light is un-polarized and is concentrated in the visible portion of the spectrum, such that ofthe detected light re
31、flected from a white surface will be between and with the spectral peakbetween and . The illumination shall be diffuse, or axially symmetric, with an incident angle of. The uniformity of the illumination on the specimen stage before any software corrections shall bewithin . The specimen stage shall
32、be shielded to prevent influence from ambient conditions.NOTE Precision improves with resolution. Therefore it is advisable to have as high a pixel resolution as is practical for thesmallest dirt specks. However, to prevent false detections arising from sheet micro-structure, the effective minimum p
33、hysicalpixel resolution must not go below .5.2 Analyser, incorporating “Equivalent Black Area” (EBA) calculations, and using a technique called the“visual impact parameter” (see 1 in the Bibliography, and Annex A). This parameter permits the system toperceive dirt and shives in the same manner, as w
34、ould a human judge.5.3 Certified calibration plates, which shall be matte and have at least one solid white area and a solid blackarea. There are to be two other image areas containing a minimum of 16 dots, each with a value differenceYc/22,4 %Yc/281,5 %0,020 mm295 %380 nm 740 nm500 nm 600 nm45 54%0
35、,002 mm2Yc/2BS ISO 5350-4:20063to their background of and . Each set of certified calibration plates is numbered and provided with acalibration certificate containing the correction factors for the -reflectance of the dots. Additionally, thecertified calibration plates shall meet the specifications
36、in Annex B. These plates are available from TAPPI1).NOTE It is known that large amounts of fluorescence in paper can cause possible problems with the calibration ormeasurement using this method. However, that effect will be normally minimal, since the reflectance values are measuredat the value, not
37、 at for brightness.6 Sampling6.1 GeneralIf the test is being made to evaluate a pulp lot, the sample shall be selected in accordance with ISO 7213. If thetest is made on another type of sample, report the source of the sample and, if possible, the sampling procedureused. From the sample received, ma
38、ke sure that the test portions taken are representative of the whole sample.6.2 Pulp sheetsFrom each test unit, select ten or more sheets having a total exposed area (both sides) of at least . Keepthe specimen sheets clean between two outer extra sheets.NOTE There may be instances where less than is
39、 examined. This may be acceptable when the quantity of dirt in thepulp exceeds the minimum required to reach a chosen level of counting precision (see 7.2) and the sample is representativeof the manufacturing process.Some pulp sheets contain deep corrugations, which may cast shadows or prevent consi
40、stent detection of thedirt specks at some locations in the sheet. Such pulp sheets shall be reformed into laboratory sheets forexamination.6.3 Slush or flash-dried pulpTake a sample and form into specimen sheets in a carefully cleaned stainless steel sheet-former, in accordancewith ISO 5269-1 or ISO
41、 5269-2. Make a sufficient number of sheets so that they have a total exposed area (bothsides) of at least . Restrain the sheets while drying on drying plates, taking care to avoid contaminationand wrinkling.NOTE In thick pulp sheets, dirt specks may be embedded throughout the thickness of the sheet
42、. When pulp is reformedinto a new product, then these embedded dirt specks may have a different impact.7 Procedure7.1 GeneralTurn on the light source. Allow the equipment to warm up and adjust the hardware settings according to theinstructions or recommendations. The system will have reached a stead
43、y-state condition when five consecutiveG.L. readings are within of each other.7.2 Calibration7.2.1 GeneralIf there is an adjustable focus on the detector, verify that the calibration-plate image is sharply focused.1) www.tappi.org25 % 55 %Yc/2Yc/2457 nm10 m210 m20,4 m22%BS ISO 5350-4:200647.2.2 Cont
44、rast calibration7.2.2.1 GeneralPlace the calibration plate with the greatest contrast flat on the stage. If a device is used to hold a sample flat onthe stage, then this device shall be used to hold the calibration plate flat.7.2.2.2 Zero adjustWith the black square in the field of view, scan the bl
45、ack area on the plate, adjust the instrument to report avalue of not less than 9 out of 255 grey levels, or of the full grey scale. Successive scans of the black areamust give results within G.L. values.7.2.2.3 Span adjustWith the white square in the field of view, scan the white area on the plate,
46、adjust the instrument to report avalue not greater than 220 out of 255 grey levels, or of the full grey-level scale (see Note). Successivescans of the white area must give results within G.L. values. A minimum of 210 G.L. resolutionsbetween the black and white squares is required. The grey-level sca
47、le shall be precise enough for each greylevel to corresponds to a step of not more than reflectance units.NOTE The percent-reflectance and G.L. are linearly related such that . To determine the G.Lvalue of the Black and White calibration plates, multiply the percentage of reported on the certificate
48、 by 2,55 providedwith the set of calibration plates.Repeat these two adjustments iteratively until both specifications are achieved.7.2.3 Equivalent Black Area calibrationMeasure each of the calibration plates. Verify that all 16 dots are detected and that the EBA results, measuredand reported, agre
49、e within of the average of all 16 dots to those determined from the data supplied withthe certified calibration plates. To calculate the EBA of the dots on the plates, multiply the nominal area, asstated in the specifications in Annex B, by the corrected contrast difference reported on the certificates providedwith the plates. If they do not match, then check the hardware and/or the condition of the calibration plates. Ifnecessary, verify the correct operation of the equipment with the manufactu
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