TM 55-1560-307-13&P c. A maintenance function assigned to a maintenance category will automatically be authorized to be performed at any higher maintenance category. d.  A maintenance function that cannot be performed at  the  assigned  category  of  maintenance  for  any  reason may    be    evacuated    to    the    next    higher    maintenance category.  Higher maintenance categories will perform the maintenance  functions  of  lower  maintenance  categories when required or directed by the commander that has the authority to direct such tasking. e.    The  assignment  of  a  maintenance  function  will not   be   construed   as   authorization   to   carry   the   related repair parts or spares in stock.  Information to requisition or otherwise secure the necessary repair parts will be as specified  in  the  associated  repair  parts  and  special  tools list (RPSTL). f.      Normally   there   will   be   no   deviation   from   the assigned  level  of  maintenance.    In  cases  of  operational necessity, maintenance functions assigned to a maintenance  level  may,  on  a  one-time  basis  and  at  the request  of  the  lower  maintenance  level,  be  specifically authorized   by   the   maintenance   officer   of   the   level   of maintenance   to   which   the   function   is   assigned.      The special  tools,  equipment,  etc.    ,  required  by  the  lower level   of   maintenance   to   perform   this   function   will   be furnished by the maintenance level to which the function is assigned.  This transfer of a maintenance function to a lower   maintenance   level   does   not   relieve   the   higher maintenance  level  of  the  responsibility  for  the  function. The  higher  level  of  maintenance  will  provide  technical supervision and inspection of the function being performed at the lower level. g.  Changes to the maintenance allocation chart will be    based    on    continuing    evaluation    and    analysis    by responsible  technical  personnel  and  on  reports  received from field activities. B-3.        MAINTENANCE    FUNCTIONS .          Maintenance functions will be limited to and defined as follows: a.    Inspect.    To  determine  the  serviceability  of  an item    by    comparing    its    physical,    mechanical,    and/or electrical characteristics with established standards through examination (e.  g.  , by sight, sound, or feel). b.    Test.    To  verify  serviceability  by  measuring  the mechanical, pneumatic hydraulic, or electrical characteristics of an item and comparing those characteristics with prescribed standards. c.  Service.  Operations required periodically to keep an  item  in  proper  operating  condition,  i.    e.    ,  to  clean (includes  decontaminate  when  required),  to  preserve,  to drain,  to  paint,  or  to  replenish  fuel,  lubricants,  chemical fluids, or gases. d.  Adjust.  To maintain or regulate within prescribed limits,   by   bringing   into   proper   or   exact   position,   or   by setting the operating characteristics to specified parameters. e.  Aline.  To adjust specified variable elements of an item to bring about optimum or desired performance. f.  Calibrate.  To determine and cause corrections to be   made   or   to   be   adjusted   on   instruments   or   test, measuring,  and  diagnostic  equipments  used  in  precision measurement. Consists of comparisons of two instruments, one of which is a certified standard of known accuracy,   to   detect   and   adjust   any   discrepancy   in   the accuracy of the instrument being compared. g.  Remove/Install.  To remove and install the same item     when     required     to     perform     service     or     other maintenance    functions.        Install    may    be    the    act    of emplacing,  seating,  or  fixing  into  position  a  spare,  repair part, or module (component or assembly) in a manner to allow the proper functioning of an equipment or system. B-3