Monthly Inspection In  addition  to  routine  inspections  and inspections  after  each  use,  as  called for by ANSI, a more thorough examination    and    testing    procedure must be performed monthly by designated personnel to check cylinders,    valves,    connections,    and hoses for air-tightness.  The operation of the regulator valves must be tested and  the  apparatus  cleaned,  sanitized, and stored. Check the cylinder pressure as described   in   Step   1.      If   necessary, replace  the  cylinder  (Step  2).    Also, examine  the  facepiece  and  breathing tube and dry the regulator as in Step 4. 8.  Check Air-Tightness Test for air leaks between the cylinder and  the  regulator  outlet  by  observing changes   in   gauge   pressure.      First, block   the   regulator   outlet   with   your hand  or  the  rubber  protective  cover. Then open both cylinder and main-line regulator   valves.      Note   the   cylinder pressure. After observing the regulator pressure, close the cylinder valve and watch the regulator pressure gauge. If the needle drops more than 100 psig in 30 seconds, leaks are present.  Do not use the apparatus if It leaks.  Close the main-line valve to conserve the air supply. 9.  Check Audi-Larm Function MSA recommends that the function of the    Audi-Larm    warning    device    be checked   by   observing   the   regulator gauge   pressure   at   which   the   alarm rings.    This  test  should  be  performed with  a  minimum  cylinder  pressure  of 1,200 psig. First, pressurize the system by opening    the    cylinder    valve    for    a moment,   then   close   it.      The   alarm should ring, indicating it has automatically    cocked.        Place    your hand   or   the   rubber   protective   cover over   the   regulator   outlet   to   block   it leak-tight.  Open the main-line valve. Slowly remove your hand or the rubber protective   cover   from   the   regulator outlet and observe the drop in pressure  on  the  regulator  gauge  and the    point    at    which    the    Audi-Larm begins   to   ring.      The   ringing   should begin  at  approximately  540  psig  and continue until the air in the system is exhausted.  If the Audi-Larm does not function  property,  the  apparatus  must be  removed  from  service.    Close  the main-line valve. 10.  Check Diaphragm Function Check  that  the  cylinder  and  regulator valves are closed and that the system is not pressurized. Gently   Inhale   through   the   regulator outlet  and  hold  your  breath  for  about 10  seconds.    If  the  negative  pressure is maintained, there is no leakage. Gently   exhale   through   the   regulator outlet  for  about  10  seconds.    If  the positive  pressure  is  maintained,  there is no leakage. Do  not  use  the  apparatus  If  air  flow through   the   regulator   Is   detected   in either test.  The regulator outlet should be sanitized after testing. 11.    Check  Main-Line  and  By-Pass Valves Operation  of  the  main-line  valve  and bypass  valve  is  tested  by  putting  on the  device  and  operating  it  normally. Venting   of   pressure   relief   valves,   or continuing    flow    of    air    through    the regulator when the user Is not inhaling, Indicates   the   regulator   needs   to   be repaired.      In   addition,   any   unusual sounds  such  as  whistling,  chattering, clicking    or    rattling    means    that    the regulator should be further checked.  if any   of   these   symptoms   occur,   the apparatus    must    be    removed    from service. Clean and sanitize the apparatus (Step 5), inspect the entire unit (Step 6), and record information on the MSA inspection   tag   or   checklist   (Step   7). Finally, the unit is stored ready for the next use (Step 3). 6