Document 8OQ46dzO0NoMaJ4vrV90ez7nm

INTHODUCTION y : Ikti itiiy wan odtrtaku to asseesthe; degree of : inoaan to fll>roaa dnot .la brake maintenance prooedares ;.y /.,"'> ;*!:S :?;>;/y^" ' ;.'i ;yy ;y';;;i:,:.yyy!',''`'yy- : on commercial vehicles ttd to provide eo(pMtiT* data ': relating to a previous etudyonoperators working on passenger ears* II INVESTIGATION u\' ' Air. aanpling took plaea la the garaga on the '<!, 1 , f/ 19th September 1968* * ti 1vy y , > ; * * Membrane filters* in; conjunction with Caaella personal samplers* suitably, modified to .provide ! * o''1 * ] \ t >**>. j a> flow. rata of 200 cms/mln. ware asad and the following /r *^ ,, i s < 3 ............v..................... 8unpl inft< procoduroi idoptod s ^t * 1 * qi p < . > r < * {* , ,, y i {, * {, > j* << (a), Personal1 aanplea were collaotad from the "brake ' t, i,f;y '. blow off operator (Mr Crone) and tha meehanio woxking in the adjacent bay (Mr Hillman) daring the blowing-off operation* The filters ware than ohaagad and replaced to ran for the rest of the shift* y:' ^ ;yy`-; yy' yFit'y;y y y'yyy" .yy ryy v y: 1 y; v (b) Static samplers were positioned at three points, A, B and C, aboat 20-28' from the source of dust generation and separata samples were collected for the morning and afternoon shifts* The sampling positions are shown in Fig* 1* The colleoted samples were subsequently resoTed to the laboratory and* after preparation* examined by projection miorosbbpy for the presence of fibres greater than 5p* (A fibre is defined as haring:an aspect ratio equal to* or greater than, 3:1)* CCATES