JIS-B-9923-1997-R2008-ENG.pdf

STD-JIS B 9723-ENGL 1977 g733b08 05'i9LUL 209 JIS æ b JIS B 99231997 JAPANESE I NDUSTR IAL STANDARD Translated and Published by Japanese Standards Association Clean room garment - Methods for sizing and counting particle contaminants in and on clean room garments ICs 19.120 Descriptors : clean rooms, clothing, uniforms, contaminants, particle size Reference number : JIS B 9923 : 1997 (E) measurement, particulate air pollutants 11 s B 9923 : 1997 Foreword This translation has been made based on the original Japanese Industrial Standard revised by the Minister of International Trade and Industry through deliberations at Japanese Industrial Standards Committee in accordance with the Industrial Standardization Law. Consequently, JIS B 9923: 1986 has been revised and replaced with this Standard. Date of Establishment: 1986-11-01 Date of Revision: 1997-09-20 Date of Public Notice in Official Gazette: 1997-09-22 Investigated by: Japanese Industrial Standards Committee Divisional Council on General Machinery JIS i 3 9923 : 1997, First English edition published in 1998-02 Translated and published by: Japanese Standards Association 4-1-24, Akasaka, Minato-ku, Tokyo, 107-8440 JAPAN In the event of any doubts arising as to the contents, the original JIS is to be the final authority. 7 O JSA 1998 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. Printed in Japan -,-,- JAPANESE INDUSTRIAL STANDARD JIS B 9923 : 1997 Clean room garment- Methods for sizing and counting particle contaminants in and on clean room garments 1 Scope This Japanese Industrial Standard specifies the measuring methods for particles having diameter of 5 ym or over to and smaller than 50 pm, and of 50 ym or larger, and fibers 100 pm or larger in length, and for the number of separable particles having diameters of 0.5 Hm or larger, 1 pm or larger, and 5 pm or larger attached in and on the stuff of clean room garments () made of cloth used in clean rooms (hereafer referred to as “clean garments”). Note () The clean room garments mean working clothes for use in clean rooms comprising a continuous garments, a set of upper and lower garments, and a coat. Remarks 1 The normative references to this Standard are as follows. JIS B 8330 JIS 3 9921 JIS K 8593 Petroleum ether Testing methods for turbo-fans blowers Light scattering automatic particle counter JIS K 8839 2-Propanol JIS K 8848 Hexane JIS P 0138 JIS Z 8122 The units and numerical values given in the traditional units and are appended for informative reference. Trimmed sizes of paper Contamination control - Vocabulary 2 in this Standard are based on 2 JIS Z 8122. Definitions The definitions of the main terms used in this Standard are as specified in 3 Measuring environment The measuring environment for particles attached to clean garments shall have a cleanness equivalent or superior to that of the clean room in which the clean garment is used. 4 following two methods : Kind of measuring methods The measuring methods shall be classified into the (1) Microscopic method This method is performed as follows: Pass sufficiently clean air for 1 min at a rate of 14X 10 m3 (14 1) per minute through an area of 0.960X m2 (960 mm) for each position of each sheet of the garment stuff at six specified positions of the garments. Then filter with a measuring membrane filter the air which has passed through the working garment and contains particles separable from the clean garment and collect the particles exfoliated from the garment on the filter surface, and count by a microscope the number of particles of 5 pm or over to and smaller than 50 pm and 50 pm or larger and the number of fibers of 100 pm or larger in length. -,-,- STD*JIS B 7723-ENGL 1777 V733b08 05L+910'i TLB D 2 B 9923 : 1997 (2) Light scattering automatic particle counting method This method is performed as follows: Move a part or the whole of the clean garment under prescribed conditions in a definite clean environment and thereby produce floating dust and measure the cleanness of the supplied air and discharged air by the counter specified in JIS B 9921. Thus, find the number of particles per unit volume of the particles exfoliated from the clean garment for respective particle diameter divisions of 0.5 pm or larger, 1 pm or larger, and 5 pm or larger from the change in concentration and the quantity of discharged air. Remarks: The counter used for measuring the particle concentration of the supplied air and discharged air shall be the same one. 5 Microscopic method 5.1 Appliances used for measurement The following appliances shall be used for measurement. Measuring membrane filter The measuring membrane filter used for collecting the particles and fibers exfoliated from the clean garment shall have a diameter of 47 mm, apertures of within 0.8 pm and a printed lattice consisting of 3.1 mm squares, and be black in colour. Filter holder with adapter The filter holder with adapter shall consist of a set of filter holders in which a sheet of the stuff of the specimen clean garment can be fitted and conically clamped between a prefilter holder with a conical inner surface capable of accommodating an air filter and a filter holder with a conical outer surface for accom- modating the measuring membrane filter, and there shall be no air leakage in the condition of the two filter holders being fastened together. m2 (929 mm'). Tweezers Petri dish or slide glass The petri dish or slide glasses used shall be capable of keeping the measuring membrane filter in a clean condition. Suction pump The suction pump shall have a sucking capacity of 14X m-3 (14 Z) per minute in the condition in which the stuff of the clean garment, measuring membrane filter, and critical orifice or flowmeter are attached. The effective filtering area on the measuring membrane filter shall be 929 X The tweezers shall have a flat end free from the danger of cutting the filter. Informative reference : A vacuum pump having a sucking capacity of 67 kPa (500 mm Hg or larger may be used. Microscope The microscope shall have a resolving power sufficient for measuring the minimum particle diameter of 5 pm, have a flat visual field, and meet the following requirements of (a) to (e). r (a) The combined magnification of the microscope shall be 50IlO and 100k 10, and the magnification of the eyepiece shall be 10 and that of the objective shall be 5 and 10. , 3 B 9923 : 1997 (b) A biocular or monocular microscope shall be used, but a stereo-microscope shall not be used. (c) The moving stage shall be capable of scanning the whole effective filtering area of the measuring membrane filter. (d) The eyepiece micrometer shall have a scale of 10 mm length divided into 100 parts. (e) The illuminator shall be able to illuminate from oblique directions, to change the brightness, to adjust the focus of the condenser lens, and in addition, to change the direction freely. (7) Counter The counter shall be able to count the number of particles by manual operation. (8) Stage micrometer The stage micrometer shall have a scale dividing a length of 1 mm into 100 parts. 5.2 0.45 vm apertures, and consist of the following : Reagents The reagents shall be used after being filtered with a membrane filter with Distilled water Isopropyl alcohol The isopropyl alcohol used shall conform to Grade 1 of JIS K 8839. Petroleum ether The petroleum ether used shall conform to guaranteed grade of JIS K 8593. Remarks: As a substitute for petroleum ether, the guaranteed grade hexane of JIS K 8848 may be used. 5.3 Measuring procedures 5.3.1 Verification and background measurement The verification and background measurement shall be performed as follows : (1) Verification of eyepiece micrometer Place the stage micrometer on the moving stage and make verification by examining, based on the stage micrometer, the number of micrometers to which the scale mark of the eyepiece micrometer corresponds, with respect to magnification of 50 and 100. Remarks: The verification of the eyepiece micrometer shall be made cover its entire scale and not be limited to its portions. (2) Background measurement Measure the background according to the procedures of 5 . 3 . 2 to 5 . 3 . 5 without attaching the clean garment to the filter holder with adapter. Repeat this operation two times and take the average of the measured values as the background. 5.3.2 Preparatory operation The preparatory operation shall be performed as follows : (i) In the measurement of particles attached to the clean garment, the measurer shall wear a -,-,- STD-JIS B 7723-ENGL 1777 Li733b08 05491Ob 87n 4 B 9923 : 1997 garment for clean room properly by a method to prevent contact with the floor or other furniture. Preliminarily clean the filter holder with adapter, tweezers, filter supporting base, and slide glasses at each measurement according to the following order: (2) (a) Remove oil by rinsing with petroleum ether. (b) Thoroughly wash in warm water using a neutral detergent and then rinse with warm water tio times. (c) Rinse with filtered, distilled water two times. (d) Remove water by rinsing with filtered isopropyl alcohol. Further, after rinsing with filtered petroleum ether, evaporate. (3) Take a sheet of measuring membrane filter out of the container using tweezers and rinse both surfaces with filtered petroleum ether. (4) Place the measuring membrane filter with its latticed surface upward on the filter supporting base and attach to the filter holder. (5) Connect the filter holder and the critical orifice or flowmeter to the suction pump by using a hose. (6) Where the specimen clean garment is packaged, take it out by cutting the package with a sharp cutting tool. In this case, never tear the package. (7) Hang the specimen clean garment with a clean hanger or the like at a position facili- tating the collection of particles for measurement in a clean environment to prevent contamination during the collection of particles. 5.3.3 Collection of particles garment shall be performed as follows : The collection of separable particles attached to the clean (1) The positions for collecting particles separable from the clean garment shall be the 6 positions shown in Fig. 1. Armpit Hip I Front side Back side Fig. 1 Positions for collecting particles -,-,- STD*JIS B 7723-ENGL I997 4733b08 0547307 727 I 5 B 9923 : 1997 (2) At the respective collecting positions on the specimen clean garment, apply the outer surface of the filter holder attached with a measuring membrane filter (refer to Fig. 2) to the outer surface of the specimen clean garment. Locking roller Fixing screw Locking ring Inlet side Adjusting screw Filter protecting mesh Cloth stuff Fig. 2 Filter holder (3) The quantity of sucked air shall be the air quantity sucked in 1 min at a flow rate of 14 X m. per minute at each particle collecting position. Remarks: Where a flowmeter is used between the filter holder and the vacuum source, the actual flow rate at the standard temperature and the standard pressure shall be determined by carrying out corrections for temperature and pressure. In this case, the standard temperature shall be at 20 “C and the standard pressure at 101.325 kPa (1 atm. 5.3.4 Preservation of measuring membrane filter The measuring membrane filter on which the particles and fibers exfoliated from the clean garment have been collected shall be detached from the filter holder by using tweezers and kept held between clean slide glasses or placed in a petri dish for use as the microscope specimen. 5.3.5 dures : Measurement Measurement shall be carried out according to the following proce- Place the measuring membrane filter carrying out collecting particles and fibrous particles (hereafter referred to as “sample”) on the stage of the microscope. In this operation, make the lines of the lattice on the sample agree with the coordinate axes of the moving stage. Where the sample is preserved in a Petri dish, make measurement by detaching the cover as required. -,-,- 6 B 9923 : 1997 STD-JIS B 7723-ENGL 1777 4733b08 05q7308 bb3 Scan over the sample surface at a low magnification and confirm that the particles are dispersed uniformly. The magnification of the microscope shall be 100 for particles of 5 pm or over to and smaller than 50 Hm and be 50 for particles of 50 pm or larger and fibers. The particle diameter divisions shall consist of particles of 5 pm or over to and smaller than 50 pm, particles of 50 pm or larger, and fibrous particles of 100 pm or larger in length. Measure the passing particles by the scale of the eyepiece micrometer while shifting the microscope stage. If the direction of the largest diameter of a particle is inclined against the scale line, estimate the largest diameter. In this case, it is unnecessary to measure the diameter by rotating the eyepiece micrometer. Where it is estimated that the number of particles of the objective particle diameter division is 1 to 500 in the effective filtering area, count the number of particles present in the whole effective filter area. Where it is estimated that the number of particles of the objective particle diameter division is 500 to 1 O00 in the effective filtering area, count the particles present in arbitrarily chosen 20 grids (refer to Fig. 3). ?y out duplicate counting. Fig. 3 Counting method Where the number of particles of the objective particle diameter division is estimated to be 1 O00 to 5 O00 in the effective filtering area, count the particles present in arbitrarily chosen 10 grids. Where the number of particles of the objective particle diameter division is estimated to exceed 5 O00 in the effective filtering area, count, for the respective particle diameter divisions, the number of particles in a definite area in each of arbitrarily chosen 10 grids (refer to Fig. 4). In this case, select either of the following (a) or (b) as the definite area in a grid so as to make the number of particles present therein about 50. (a) An area of which the longitudinal length agrees with the entire scale of the eyepiece micrometer and the lateral length agrees with the entire width of the grid. (b) An area of which the longitudinal length covers a part of the eyepiece micrometer and the lateral length agrees with the entire width of the grid. -,-,- 7 B 9923 : 1997 Where the number of particles is very large, this part only may be taken as the definite area. Eyepiece micrometer scale +Grid Fig. 4 Method of selecting definite area in a grid (10) Where a particle lies on the upper or left side bound