TM 10-6640-233-10 1-20.  Laboratory  Operating  Procedures.  The  following  scenario  pertains  to  the  AOAP  Mobile  Laboratory  processing selected aeronautical and nonaeronautical oil samples in a tactical environment. Further, it is not to be conceived as the "ONLY" way of performing specified AOAP analysis. a. The process begins with the soldier in the field who takes an oil sample and fills in applicable data elements on a DD Form 2026, Oil Analysis Request. The completion of this form, which accompanies the sample to the laboratory, is critical to the success of the analysis, since all data relating to the component from which the oil was taken is entered off this  form.  Component  serial  number,  hours  since  last  oil  change,  and  hours  since  last  overhaul  are  examples  of  data required  by  the  evaluator  for  accurate  assessment  of  component  wear  or  changes  to  the  lubricating  oil's  physical properties. b. On receipt of the oil sample at the AOAP Mobile Laboratory, the components sample's header information is entered in the AOAP Mobile Laboratory's Standard Data System (SDS) computer. The SDS assigns an index number to each serial numbered component. The index number is where the current and/or historical analysis information is stored in the computer, which is retreived by entering components serial numbers. c. The   oil   sample   at   this   time   can   have   spectrometric   or   physical   property   analysis   performed,   since   the aeronautical  oil  samples  require  only  spectrometric  analysis  to  be  performed,  except  for  selected  AH-  1's  components requiring ferro graphic analysis. Thus, for discussion purposes ONLY, oil analysis process will begin with spectrometric analysis test, which is performed on all components enrolled in AOAP. d. The oil sample is analyzed for up to 15 wear metals on the spectrometer. The spectrometer is interfaced with a Wang MICROVP-2 computer system. This system has been loaded with AOAP wear metal guidelines for components enrolled in AOAP. If element(s) exceed(s) the specified spectrometric guidelines for that component, then the evaluator reviews analysis data and makes a recommendation to the owning unit. These recommendations can range from an oil and filter change to the removal of the component from service. To ensure the proper operation of the spectrometer, the operator   performs   daily   standardization   checks   on   the   instrument   before   each   day's   start   up.   However,   if   the spectrometer does not pass these prescribed daily standardization checks, then a complete standardization is performed. Additionally, periodic standardization checks are made throughout the day. At a minimum, these checks are made when switching from analysis of aeronautical to nonaeronautical samples (and vice versa), or whenever the spectrometer has not been operated for 30 minutes or more. e. Physical property testing is performed on nonaeronautical engine and transmission oil samples to determine the on-condition of the oil in these components. f. The  Crackle  Test  is  performed  utilizing  a  hot  plate  set  at  300  to  350  degrees  Centigrade  (150-175  degrees Fahrenheit) surface temperature to ascertain presence of water contamination. This test is accomplished by placing one drop of oil on the surface of the hot plate. A positive test is indicated by an audible crackling and spattering of the oil. g. The determination of the viscosity of used oils is performed using a Direct Readout Viscometer. The viscosity reading is obtained by immersing the viscometer's vibrating sphere into the nonaeronautical oil sample. If the viscosity reading  of  the  used  oil  sample  obtained  is  below  the  prescribed  lower  criteria  guidelines,  then  additional  testing  is conducted to determine if fuel dilution, contamination, or lubricant degradation has occurred. Additionally, if the viscosity readings obtained are above the upper criteria, then the evaluator may recommend an oil and oil filter change. 1-33