1、BRITISH STANDARDBS ISO 5350-3:2007Pulps Estimation of dirt and shives Part 3: Visual inspection by reflected light using Equivalent Black Area (EBA) methodICS 85.040g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g
2、48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS ISO 5350-3:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 February 2008 BSI 2008ISBN 978 0 580 54049 3National forewordThis British Standard is the UK implementation
3、of ISO 5350-3:2007. It supersedes BS ISO 5350-3:1997 which is withdrawn. The 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 this committee can be obtained on request to its secretary.T
4、his 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/corrigenda issued since publicationDate CommentsReference numberISO 53
5、50-3:2007(E)INTERNATIONAL STANDARD ISO5350-3Second edition2007-12-01Pulps Estimation of dirt and shives Part 3: Visual inspection by reflected light using Equivalent Black Area (EBA) method Ptes Estimation des impurets et bchettes Partie 3: Examen visuel par lumire rflchie utilisant la mthode de la
6、surface noire quivalente (mthode EBA) BS ISO 5350-3:2007ii iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Principle. 2 5 Apparatus 2 6 Sampling and preparation of test piece . 3 6.1 Sampling 3 6.2 Pulp sheets 3 6.3 Never-dried pulp . 3
7、 7 Procedure 3 7.1 Pulp with a low dirt content . 4 7.2 Pulp with a high dirt content . 4 8 Expression of results . 4 8.1 Calculation. 4 8.2 Results . 5 8.3 Precision 5 9 Test report . 6 Annex A (normative) Comparison chart 7 Bibliography . 8 BS ISO 5350-3:2007iv Foreword ISO (the International Orga
8、nization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). 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 establis
9、hed has the right to be represented on that committee. International organizations, governmental and non-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
10、. 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 Standards adopted by the technical committees are circulated to the member bodies for voting. P
11、ublication as an International 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 patent rights. ISO shall not be held responsible for identifying any or all such pate
12、nt rights. ISO 5350-3 was prepared by Technical Committee ISO/TC 6, Paper, board and pulps, Subcommittee SC 5, Test methods and quality specifications for pulps. This second edition cancels and replaces the first edition (ISO 5350-3:1997), which has been technically revised. This edition is based on
13、 TAPPI T 213 om-01. 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: Visual inspection by reflected light using Equi
14、valent Black Area (EBA) method Part 4: Instrumental inspection by reflected light using Equivalent Black Area (EBA) method BS ISO 5350-3:2007vIntroduction This part of ISO 5350 is complementary to ISO 5350-1, which concerns visual inspection of laboratory sheets by transmitted light and ISO 5350-2,
15、which concerns visual inspection of mill sheets by transmitted light. This part of ISO 5350 is based on visual inspection by reflected light using the Equivalent Black Area (EBA) method. ISO 5350-4 is based on automatic inspection by reflected light using EBA. BS ISO 5350-3:2007blank1Pulps Estimatio
16、n of dirt and shives Part 3: Visual inspection by reflected light using Equivalent Black Area (EBA) method 1 Scope This part of ISO 5350 specifies a procedure for the estimation of the visible dirt and shives by reflected light using the Equivalent Black Area (EBA) method in pulps. It is, in princip
17、le, applicable to all types of dry or wet pulp, manufactured in sheets or rolls, including recycled pulp. NOTE The result of inspection by reflected light represents only the number of specks visible on the surface or near the surface of the pulp sheet. Particles which are embedded in the sheet cann
18、ot be detected. 2 Normative references The 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) applies. ISO 5269-1
19、, Pulps Preparation of laboratory sheets for physical testing Part 1: Conventional sheet-former method ISO 5269-2, Pulps Preparation of laboratory sheets for physical testing Part 2: Rapid-Kthen method ISO 7213, Pulps Sampling for testing 3 Terms and definitions For the purposes of this document, th
20、e following terms and definitions apply. 3.1 sheet sheet of pulp taken from a bale, or a part of a roll of pulp 3.2 test piece area taken for inspection 3.3 laboratory sheet sheet formed from disintegrated pulp BS ISO 5350-3:20072 3.4 contrary in pulp any unwanted particle, of specified minimum size
21、 and having a contrasting colour with respect to the surrounding area of the sheet, according to the comparison chart given in Annex A 3.4.1 dirt any non-fibrous contrary 3.4.2 shive sliver of wood, or fibre bundle 3.5 Equivalent Black Area EBA area of one of the round black spots (a Yc/2value of 2,
22、4 %) in the Comparison Chart (Annex A) that has the same apparent area when examined visually upon its white background (a Yc/2value of 81,5 %) as does the dirt speck when examined visually upon the particular sheet in or upon which it is embedded NOTE 1 A larger “grey” dirt speck has the same visua
23、l impact as a smaller “black” one when viewed on the same sheet and under the same conditions. NOTE 2 The Equivalent Black Area (EBA) of a dirt speck determined visually is generally less than its physical area. The EBA approaches the physical area only as the speck becomes large. 4 Principle The te
24、st pieces to be examined are inspected on both sides with reflected light. The number and area of all contraries larger than a specified value and showing contrast, with respect to the surrounding area of the sheet, are estimated. The total EBA of the contraries is calculated and the total number an
25、d the total EBA of dirt and shives are reported as the number of contraries per square metre, and as square millimetre per square metre (number of contraries/m2and mm2/m2). 5 Apparatus 5.1 Illumination device, a suitable light source or a viewer for the investigation of sheets in reflected light. Li
26、ghting arrangements shall give about 1 700 cd/m2of white light or daylight on the surface of the test piece. Because the light affects equally the appearance of both the contraries and the comparison spots on the charts, the intensity of illumination is not critical. NOTE The luminance can be measur
27、ed by a luminance meter. For grooved pulp sheets, care should be taken to position the light source so that the pulp ridges do not cast shadows. The results can be significantly different on the same pulp sheet if the counting has been carried out with or without a magnifying glass or similar device
28、s. Do not use a magnifying device for dirt size estimation. 5.2 Comparison chart, the actual chart is a photograph (approximately 89 mm 127 mm) of a series of round black spots of various areas on a white background. The reflectance of the white background is (81,5 1,0) % and that of the black spot
29、is (2,4 0,4) %. In accordance with Graffs findings (see Reference 1), all the round spots on the present chart, except those listed, are correct to within 10 % or 0,005 mm2, whichever is the larger. For special accuracy, these designated areas should be changed to those given in parentheses: 1,00 (1
30、,08); 0,80 (0,76); 0,60 (0,58); 0,40 (0,42); 0,30 (0,31); 0,25 (0,26); 0,20 (0,21); 0,15 (0,16); 0,10 (0,11); 0,09 (0,10). The chart is included in normative Annex A. BS ISO 5350-3:20073Only the round spots are used for the analysis. This Comparison chart is identical to the one used in TAPPI T 213
31、om-01. These charts are available from TAPPI (http:/www.tappi.org). Plastic-covered cards, transparencies, photocopies, or printed charts will not give equivalent results and shall not be used in this method. Do not use the chart in ISO 5350-1 and ISO 5350-2, as that chart is intended for examinatio
32、n by transmitted light. 6 Sampling and preparation of test piece 6.1 Sampling If the test is being made to evaluate a pulp lot, the sample shall be selected in accordance with ISO 7213. If the test is made on another type of sample, report the source of the sample and, if possible, the sampling proc
33、edure used. From the sample received, select specimens so that they are representative of the whole sample. 6.2 Pulp sheets From each test unit, select 10 or more sheets (preferably 20), each sheet having an exposed area on each side of at least 0,15 m2. Sheets taken from the usual pulp bale are sui
34、table. Keep the specimen sheets clean between two extra outer sheets. In thick pulp sheets, dirt specks may be embedded throughout the thickness of the sheet. When pulp is reformed into a new product, these embedded dirt specks may have a different impact. 6.3 Never-dried pulp Take a sample and form
35、 it into specimen sheets in a carefully cleaned stainless-steel sheet-former in accordance with ISO 5269-1 or ISO 5269-2. Make a sufficient number of sheets so that they have a total exposed area (both sides) of at least 0,4 m2. Dry the sheets under restraint on drying plates, taking care to avoid c
36、ontamination and wrinkling. 7 Procedure Examine the areas selected for counting. Use the comparison chart (Annex A) to estimate the Equivalent Black Area of each speck. Record the estimated area of each speck. During the count, if any odd speck of dirt is encountered, which appears unusual, e.g., a
37、crushed insect or a blotch of dirt which is definitely determined as not being representative of the shipment (ascertained by looking over additional sheets), ignore it. A shive can be defined here as a dirt speck having an aspect ratio of at least 3 to 1. Shives may be counted as dirt specks if the
38、y are visible when viewed at an angle normal to the general direction of the pulp sheet, or they may be recorded separately if this information is needed. BS ISO 5350-3:20074 7.1 Pulp with a low dirt content Examine both sides of the specimens in a dust-free place, preferably on a bench top covered
39、with a large sheet of clean paper and after making sure that the hands are clean. View the pulp sheets at right angles to its general surface direction. NOTE The right angle is particularly important for grooved pulp sheets, since the sheet area is calculated by simple geometry and ignores the incre
40、ased area of the sheets caused by the grooves. If the sheet and its contraries are viewed from an angle normal to the general surface direction of the sheet, the effect of the grooves tends to be cancelled. Carefully brush away any loose dirt specks on the surface. Check each remaining dirt speck th
41、at has an EBA of 0,04 mm2or larger. Record the EBA of each dirt speck in square millimetres. When estimating the EBA of a coloured speck or a black speck on a white or coloured sheet, proceed to select from the Comparison chart, with its white background, an appropriate black spot that is equally no
42、ticeable. If they have the same noticeability or EBA, both the speck and the then selected spot become indistinguishable at the same distance when moved away from the eyes. 7.2 Pulp with a high dirt content If the pulp is dirty and a variety of dirt specks are visible on the sheets, the specks may b
43、e too numerous to render tedious the examination of the required area of the sample. In such a case, select a particular reference spot on the Comparison Chart that has an EBA such that there will be on the average at least one such sized speck, or larger, to be found on each 500 cm2of the exposed s
44、urface of the specimens. (The size of reference spots selected might vary from 0,08 mm2for fairly clean pulp to 0,25 mm2or more for a dirty pulp.) Make a mask for a sheet of the pulp approximately the colour and size of the specimen sheets, having an opening at its centre, or a corner cut away, of o
45、ne-fifth of its area. Examine both sides of the specimens in a dust-free place. View the pulp sheet at right angles to its general surface direction (see the Note in 7.1). Without using the mask, carefully brush away loose surface dirt. Then check each remaining dirt speck that has an EBA equal to o
46、r greater than that of the reference spot selected. Record the EBA of each speck in square millimetres. Using the mask, check each dirt speck on the exposed pulp surface that is smaller than the reference spot and equal to or greater that 0,04 mm2. Record the EBA of each dirt speck in square millime
47、tres. 8 Expression of results 8.1 Calculation For all contraries (or separately as dirt and shives, if required), calculate the total number and the total area of contraries. 8.1.1 Pulp with a low dirt content Using simple geometry, measure the total area of both sides of the specimen sheets and rec
48、ord it in square metres. Ignore the increased sheet area caused by grooves. For all contraries, calculate the total equivalent black area (EBA) on both sides and record it in square millimetres. Calculate the total square millimetres of contraries per square metre of surface examined (mm2/m2) and th
49、e total number of contraries per square metre of surface examined (number/m2). BS ISO 5350-3:200758.1.2 Pulp with a high dirt content Using simple geometry, measure the total area of both sides of the specimen sheets and record it in square metres. Calculate the total EBA on both sides, by totalling the EBA of the larger specks on the entire area examined and adding 5 times the EBA of the smaller specks observed in 7.2. Calculate the total square millimetres of contraries per square metre of surface examined (mm2/m2) and the total number
