ENGINE DIAGNOSTIC TEST PROCEDURES Section 6 • MEASURE SMOKE INTENSITY (Continued) Operating Instructions NOTE:  To make sure that there are no soot particles of  previous  tests  in  the  sampling  probe  or  hose which  might  influence  the  measuring  results,  hose and   sampling   probe   have   to   be   blown   out   with compressed air before the test.  A check should be made by pumping fresh air through a filter disk.  The disk must not darken. 1. Install the sampling probe as follows: a. When  used  with  an  open  exhaust  stack,  the probe  must  be  used  with  the  standard  probe shield  and  inserted  axially  into  the  end  of  the pipe,  keeping  away  from  the  wall.    Normally,  it will be convenient to use the furnished clamp to position and fasten probe in stack. b. For    closed    stack    installations,    the    standard probe    with    the    tip    shield    removed    can    be inserted  through  a  snug  fitting  hole  in  the  side of  the  stack.  Care  must  be  taken  to  keep  the probe at 90° with the flow, to eliminate velocity effects. 2. If   samples   are   taken   from   the   exhaust   systems operating at pressure over 2.5 kPa (10 inches H20) from barometeric pressure, then correction must be made for density of the sample.  A typical correction chart is furnished with the smoke meter. 3. Insert  sampling  probe  (1,  Figure  30)  into  exhaust pipe. When possible, avoid locating near a bend. 4. Cock  the  pump  (3,  Figure  30)  by  pushing  plunger knob   (5)   all   the   way   in   until   latch   holds   spring compressed. 5. Unscrew cap nut (2, Figure 30) to allow insertion of clean    filter    disc    and    clamp    filter    by    moderate tightening of cap nut. 6. Release suction stroke by squeezing rubber bulb (4, Figure 30). 7. Loosen cap nut and remove filter discs. 8. Repeat  Steps  4,  5,  6  and  7  until  three  uniformly darkened discs are obtained. 9. Compare  sample  discs  with  "Bacharach  Oil  Burner Smoke Scale," represented in Chart C. IMPORTANT DO   NOT   COMPARE   SAMPLE   DISCS   WITH SMOKE SCALE REPRESENTED IN CHART C. USE ONLY THE ACTUAL BACHARACH SCALE. Order Bacharach Oil Burner Smoke Scale from: A.  A.  Englehardt  Company 6117  North  Elston  Avenue Chicago, I L. 60646 Figure 30.  Obtaining Smoke Sample with SE-2580 1. Sampling Probe 4. Rubber Bulb 2. Cap Nut 5. Plunger Knob 3. Pump 6. Exhaust Stack CGES-240-4 Printed in United States of America Page 40