TM 55-4920-328-13 1.        Temperature    and    torque/pressure    digital indicator  1A1.    The  temperature  and  torque/  pressure digital   indicator   (1,4,   figure   1-22)   is   a   rack-mounted instrument used for display of temperatures and torque/ pressures  sensed  in  an  engine  under  test.    The  unit  is divided into two panels: temperature display in degrees F  and  torque/  pressures  in  inch-pounds.    The  unit  is powered from the system 117v ac, 60 Hz power system. The   temperature   display   section   of   the   unit   accepts analog signals from iron-constantan and chromel-alumel thermocouple networks.  Selection of the input signal is made  on  the  data  selector  assembly  (7).    The  input signals are referenced to the  150 ° F stable temperature thermocouple junction (11).  The digital display consists of four-digit values provided by the illumination of neon glow  tubes.    A  DISPLAY  control  (2)  provided  on  the panel   is   placarded   HOLD   and   OFF.      A   FUNCTION control  (3)  is  provided  on  the  panel  and  is  placarded TEST   and   RUN.      In   the   TEST   position,   150 °F   is displayed   on   the   panel   to   verify   the   indicator,   (with. zero input).  The temperature display range of the unit is ° to  2,400°F.    The  torque/  pressure  display  section  of the   unit   accepts   analog   signals   from   remote   torque transducers  over  a  range  of  0  to  100,000  inch-pounds and  from  pressure  transmitters  over  a  range  of  0  to 1,000    psia,    psig,    or    inches    hg,    depending    on    the functional loop selected on the data selector assembly. The DISPLAY control (5) and FUNCTION control (6) are identical in function to those in the temperature indicator unit. 2.        Data    selector    assembly    1A2.        The    data selector  assembly  (7,  figure  1-22)  is  a  rack  mounted chassis  assembly  installed  in  the  upper  portion  of  the diagnostic  sub-module.    The  unit  is  19.00  inches  wide, 4.35  inches  high,  and  13.00  inches  deep,  exclusive  of the track slides.  The front panel mounts 45 back-lighted pushbutton   switches   which   individually   select   engine temperature    or    torque/pressure    analog    signals    for multiplexing    through    the    data    multiplexer    (14)    and display  on  the  temperature  and  torque/pressure  digital indicator  1A1  (1,4).    The  switches  are  arranged  in  left and right groups of 21 switches each, with a vertical row of  three  switches  centrally  located  between  the  groups. The left group is numerically placarded and arranged in three  horizontal  rows  of  seven  switches  in  each  row, numbered   from   1   through   21.      The   right   group   is numerically placarded in three horizontal rows of seven switches  each,  numbered  from  23  to  43.    The  vertical center row is placarded R/CAL, MAN, and AUTO, top to bottom.    The  front  lens  of  each  switch  is  replaceable without  removal  of  the  switch  body.    The  unit  design includes  span  and  zero  potentiometers,  10  rear  panel connectors, and the chassis assembly.  The left group of 21     switches     are     individually     depressed     to     select temperature   relay   channels   incorporated   in   the   data multiplexer    (14).        When    a    switch    is    depressed,    a mechanical    interlock    acts    to    disengage    any    switch previously actuated.  The right group of 21 switches are used   to   individually   select   torque   or   pressure   data channel   relays   in   the   data   multiplexer,   and   function identically to the group of 21 switches on the left side of the   panel.      The   top   switch   in   the   center   row   is   a momentary    pushbutton    switch    used    to    actuate    the R/CAL function for a periodic check of pre-set values of the torque system.  The middle switch in the center row, marked    MAN,    and    any    function    switch    must    be depressed for the function being checked.  Not all of the switches on the front panel are functional; switches 19, 20, 21, 22, 24, 34, 35, 37, 38 and 43 are not connected at  this  time.    The  numbered  switch  functions  are  as follows: 1.  Exhaust Gas Temperature No.  1 2.  Exhaust Gas Temperature No.  2 3.  Exhaust Gas Temperature No.  3 4.  Exhaust Gas Temperature No.  4 5.  Ambient Temperature No.  1 6.  Ambient Temperature No.  2 7.  Compressor Discharge Temperature No.  1 8.  Fuel Supply Temperature 9.    Compressor  Discharge  Temperature  No.    2  10.    P. T.  Bearing Scavenge Temperature 11. Bearing No.  2 Scavenge Temperature 13.  Engine Oil Inlet Temperature 14.    Engine  Oil  Outlet  Temperature  15.    T63  Ambient Temperature 16.  T63 Hot Air Temperature 17.  T63 Customer Air Bleed Temperature (Ambient) 18. T63 Customer Air Bleed Temperature (Primary) 23.  Torque 24.  Pressure (Not Connected) 25.  Torque Pressure (0 to 200 psig) 26.  Torque Boost Pressure (0 to 200 psig) 27.  Gearbox Oil Pressure (0 to 25 psig) 28.  Engine Oil Pressure (0 to 100 psig) 29.  Engine Oil Scavenge Pressure (0 to 200 psig) 30.  Fuel Supply Pressure (0 to 100 psig) 31.  Fuel Pump No.  1 Pressure (0 to 100 psig) 32.  Fuel Pump No.  2 Pressure (0 to 100 psig) 33.  Fuel Manifold Pressure (0 to 1,000 psig) 36.  Oil Filter Pressure (0 to 200 psig) 39.  Compressor Discharge Pressure (0 to 100 psig) 40.  Compressor Discharge Pressure (0 to 300 psig) 44. R/CAL 45.  MAN (data selector controls multiplexer relays) 46.  AUTO (for computer operation) (not used) 1-31