TM 55-4920-328-13 (3) NI Speed - N1% (4) Nil Speed - N2% (5) Torque - TORQUE (6) EGT - Tt9 (7) Pressures: (a) Inlet Oil - Pofo (b) No.  2 Bearing - P2brg (c) Gearbox Oil - Pogb (d) Fuli Manifold - PFM b.   At installation of a performance panel on the vertical tape indicator assembly, the three slide switches on  the  indicator  must  be  correctly  positioned.    Typical uses   of   the   scales   on   a   panel   are   explained   in   the following text: (1) Horsepower - Hp scale Example: A T53-L-13 engine is being tested at military power  at  an  ambient  temperature  of  BOF. To   determine   if   the   engine   is   delivering sufficient     horsepower,     observe     the     HP scale, locate the MIL column, then observe the   80   graduation   in   this   column.      The indicator   tape   must   be   at   or   above   the temperature graduation 80 on the panel.  A lower    tape    position    indicates    a    loss    of horsepower. (2) Fuel Flow - WF scale Example: The engine is being operated at 75% power at   an   ambient   temperature   of   40F.      To determine    if    fuel    consumption    is    within specified    limits,    observe    the    WF    scale, locate the 75% column, then observe the 40 graduation   in   this   column.      The   indicator tape must be at or below the 40 graduation on  the  panel.    A  higher  reading  indicates excessive fuel consumption. (3) NI Speed - N1% scale Example: This scale on the panel has three columns: BLEED,   MAX   NI,   and   IGV.      The   BLEED column displays the range during which bleed band closure should occur.  MAX NI provides the maximum    operating    limits    for    ambient    temperature ranges from ° to 100 °F. The IGV column is graduated to  indicate  the  NI  speed  at  which  the  inlet  guide  vanes should open on increasing speed. (4) Nil Speed - N2% scale Example: An  engine  is  being  tested  at  military  power at   an   ambient   temperature   of   75 °F.      To determine if performance is within acceptable  limits,  observe  the  MIL  column, estimate the 75-degree position (approximately half way between the 45 and 100  graduations),  and  note  the  position  of the   indicator   tape   which   should   be   at   or below   the   estimated   position.      The   OSG LIMIT  column  on  this  scale  provides  band for  two  fuel  flows,  LO  and  HI,  at  which  the Nil   speed   should   be   limited   by   the   fuel control overspeed governor. (5) Torque - TORQUE scale Example:. Provides    display    of    engine    output    shaft maximum torque limits for different periods of time. (6) Exhaust Gas Temperature - Tt9 scale Example:. Provides    operating    temperature    limits    at different    power    settings    as    affected    by ambient  temperature.    The  scale  indication should be at or below the limit graduations. (7) Pressure   -   Pofo,   P2brg,  Pogb,   and   PFM scales Example: These scales provide graduations for minimum    and    maximum    ranges    for    the applicable pressures being monitored. 3-4. Use of Data Selector Assembly 1A2. The  diagnostic  sub-module  contains  the  data  selector assembly  1A2  (7,  figure  1-22)  used  during  selection  of parameter  readout  during  test  of  an  engine.    The  data selector assembly is used in conjunction with the digital readout card (3, figure 7-2), contained in the card holder inside the control cab module.  During test of an engine, certain temperature, torque, and pressure test parameters are monitored by the use of the information provided on the digital readout card, combined with 3-2