Document 7ObzKZyYaOZx6dndOBq5yq5dB

KAlflOOHLSE 31 at kareh Senior Inspector of Wines, Wince Department, S&&22SOS- 66 AJlfllS In considering tie selection of 12m Ibsmoi Precipitator bb etonflerd instrument for dust collection and assessment, Z am not detracting In Op y fro* the Ketfcon Victor Kenimoter ae a general dust sampler for nornal field work. aa . Although the duet counting efficiency of any Konlaeter la admittedly lev ard io selective with respect to else, it la easily recognisable aa the seat coepaet anl simplest sampling deviee for gulch esaaassent of dust ecnoantretiaa* is any wording place. Similarly, such an instrument aa tbs Thermal Precipitator. Widget Zoplnger* or the Cassell a 'Scihlot', could hardly be considered mutable for &bd1 UftSererocwS dust sampling as they are used snlmly for sampling over varying perlode of tlto. Actually, in the s3orlty of working places toere high dust counts lava been recorded, the fact that ceBdltle&a were extremely dusty could easily have bean assessed without the use of any dust sapling instrument, and Z think that this is eoaslatemt with tbs pinion vetoed by Brinkar 4 Hatch P, W. It has been proved that different sampling imetrvaante exhibit greet variations in their behaviour with different kinds of duet and with particles of different also In the same dust. Therefore, It appears impossible to determine general convert!on factors or to compare instruments on the basis of their absolute efficiencies onlese tbd tost to be sampled is completely homogeneous. To emphasise this point Z would like to quote from the 3.1.0, Publication "Guide to the Prevention sad Suppression of Dust, 1965 fr. 306) w *t N. A "la selecting a waagUng system it is first neoeasuy to decide whether it should be based en the weight ef tost in the air or on the number of partloles which are considered to be in the dangerous else range. x ^ ~v ;' X, Allowemsa must, however, be mode for the particular characteristics of different sampling inatiMmmnts eai procedares. Blffercncas in these respects create difficulties in respect c comparability of resuite. Hot only do the different instruments exhibit varying effleiendea in oollcctloa, but they alec have different sejectivltlca with, regard to the partidies being sampled. An example from one series of tests makes this dear. Side~hy- side sampling with a thermal precipitator sal a fcnaiaeter ves perforated on the dust created by e series of different underground operations. Siw following results ware obtained s PLAINTIFFS EXHIBIT i a WVJ4268 4 PLAINTIFFS EXHIBIT -1Q.SZA.J1 WV-004268 Operation 1 2 3 i* 5 6 7 8 9 Dual concentration {number) Thermal Precipitator Xonimetar 1,230 360 1*0 U$o 570 350 210 2*0 380 1S2 87 '103 . 85 118 89 66- 217 161 Zt will be neen that the health risk* of operatlone 2 and b are the greatest according t-o the thermal precipitator, while the konlmeter indicates that operation 6 presents the greatest hasard." The ideal instrument la one tfslch will collect a represent ative sample of the duet a it exists In the esvirormest, that la without altering the particles or their dietributim in any way, and will enable the resalt to he quickly and easily assessed. Zt should sarnie only the respirable fraction of the deal with the ease selectivity as the human respiratory system and provide information over an extended period of tine with regard not only to the average concentrations, but also to ephemeral fluctuations. Zt must be of staple end rugged construction for nee under the conditions found in a mine, and automatic operation voald ha cost desirable. Although the shove points illustrate the eptisua re<iire seats in guy dost aaapMfg imrtwwBt, than 1b however, instruaont at present available, capable of fulfilling all these requiresente. Boat of thorn arc selective in operation or break up aggregate^ sxd give an exaggerated reading of the number of fine particles present. Without doubt, the ehoiee beeasoe quite restricted and it generally fails on an instrument which allows a large number of samples to be taken at different places in the .shortest possible time, or else in a eontlnacue aeapliag device. Ae Z stated before, the Konimeter la a suitable sampler for normal routine dust sampling underground, and it fulfills several of the previous mentioned requirement* via: rugged construction, large number of samples which can bs eamplad, the air volume sampled is fatly large, it ia of a handy sire ani once loaded is always reedy for sampling. In fact, Z for eae consider it the-moat-practical .instrument far routine fleet aaepllAg. However, it also baa great drawbacks, tha moat important being ite unpredictable performance or efficiency under varying conditions. Similar instrument will give widely different results in the same environment. -V . r" It has a tenancy to break up aggregates wing iO'the high impact velocity. Thera Is a difficulty in evaluating heavy concentretiona. Because of its yapid scarpling rate - about 0.1 aewta - the eosplee ora only Instantaneous valuea which Bay differ coneldcrobly fTos the average values. Also, the quantity of dust collected In the sample depends to a large extent on the nature and thleknaea of the adhesive fill. Samples ere often crowded out with background count due to bubblee in foreign natter In the adhesive fila. This phenomena has increased since the uea of dark-field Illumination, and froa oar v own experience, we fowtl it necessary to switch fro* using Sommeter jelly to the IyloI-Po tro1am Jelly solution. Sven so, ee have received reports on the difficulty caused by excessive background. ia.b counts In this solGtlbA~{Sepsrt&ent of UineeV^W , , ueopudfaree oeeaeiens In the laet too years, tc - '"5 Of \.y' ''""`SarXylol-PetroleBs Jelly solution a a they vvoeirme experiencing difficulty in orarcoming background intrusion;. According to the International Imboor Office's *Guide to the Prevention and Suppression of Duet in Klnlng, Tunnelling and Quarrying, 1969*, the Koniaotcr Is hot eo suitable for precise dust measurements, hat it is of value when used la conjunction with other instrument* which give ere precise laforaatlnn shoot the nature of the duet oonoaBtra^ODj^^^ The a1 Xbr a sere preelee instrument, such ss the lhansal Predpitetois.ls beceatrg iBcroasii&ly eelf-evident each year. *? have a highly technical and qualified staff shoes roepoaeihmiy * liee in the eontrol of test auppresdon In all Bine*, quarries, redaction end crashing plants throughout the State. It is our doty to convince Kin* and Ccopany Official of the need for Increased duet control. This la not always easy when oar sole aethod of dust sampling ie per sodium of the Konlmeter. Dust ooante tendered by our Department have, on several occasions, bean queried by seas of these Companies on their reliability. Wster-vspeer and foggy atmosphere* have sometimes been the easae of diseoaaloe on bigs results. BrosUng-up of aggregate concentrations have bean other casae*. Until ve convinced the Kimee to atandarilse on Saxfc-Pleld Illumination for particle countings, differedee of opinion arose on vjaoee dost count see correct -- dark field illumination invariably gave higher reedInge. Various methods for sampling the asbestos duet et Wittenooa end garble Bar here been tried in conjunction with Eonlmeter Sampling (e.g. Tyndallmeccrpe and Midget Saglngerj^rith no effective results. The Thermal Predpltator^if acquired, mould not be used for routine dost sampling, Ite main requireaests weald bo to provide a standard for ccgypariaco with ether laatrcnents, which would be universally accepted. &Provide a precise instrume&t for carrying out syeaial tlone iota any fecit of the Industry whether surface plant or umergroaod. Somalia from atxeh an inetrcaaat would be aero eocgptable whenever there was any variance of opinion. 6*~ V Then any place Is 1a doubt due to changing esriroment. Primary Cruahirg operations, ere pass contra. operations, areas affected by secondary blestlog operations, multi-operations In dose proximity (Mineral Sanaa Treatment Plante), the need ft? a continuous sampler is multiplied. 1 JS. *. ** It bee been necessary on meerouQ occasions In tbe post, *hen investigating anooaldua conditions, to determine tbs dost concentrations over o period of turn doe to changing envLronaent throughout the shirt. This has applied both surface end undarground. To carry oot such a survey, there ere e jmaber of points to "be deterslned e.g. the quantities and characteristics of the dust liberated; the dustiest operotlore, places and equipment; enl the variations in dost concentrotions in the eourae of a shift or betseen shifts. The informtion obtained is necessary to plea effective tteaearea for prevention end suppression of duet in the scat efficient Banner. To carry out sees a survey St la neoeaaavy to obtain eoae fora of continuous sampler. In the peat e have obtained tbe use of a Uldget Inplnsor, or a Tfcaraal Precipitate^ fraa the School of Hines. However, thi^-fea not aiveya^ convenient for us or the School* Although it la agreed that the necessity for obtaining 100 efficiency in dost particle concentretlone is not very great, and tbat the rain characteristic to be deterslaad la 'Aether or not an industrial haawrd exiite in certain wcrtclag places. 1 would like to add that the need for a world-wide use of e standard'sethod of dust determination, to serve as a basis of cooparlacn of cordlticns in different countries and different industries, was eapbesized at the Silicosis Conference in South Africa a a far bade as 1930 (DnLr&er A Batch P.151). There ie no doubt that the Thevtsal Precipitator la fast ^ beccaing that recognised standard. It ie also quotad in Drinker A Batch* publication "Industrial Duet* P.150 that, at the tlae of publication of this book, the Therasl Precipitator bad net been used to any extant in isdaatry, trtf that its Barits had not been folly explored. Sowever, it la now regarded aa one of the soot raliable duet --^ ^fr loatruBsnt*, sod aay be used for eawpling all klnSa of airborne pertidea, both organic an! anorganic, at high or loo concentrations - J.L.Q. "Guide to the Prevention and Suppression of Dust, 1965 P.326. This concludes ay Tiers on the cubjeet, sad although they W appear lengthy in detail, X eaeusidcr that as It ie the responsibility of eur Dajertomnt to taprove ard aaintain tbe standard of ventilation and dust suppression In this State, we should use the beat available In thla regard. MSTRTCI/XWSPECTCK OP STiKSS (Tent.)