TM 55-4920-328-13 5-5.  Checkout of Control Cab Instrumentation. The procedures for checkout of control cab instrumentation  contained  in  the  diagnostic  submodule (Unit   1)   and   the   analyzer   sub-module   (Unit   2)   are contained in chapter 2.  Other instrumentation mounted in the control cab and depicted in figures FO-2 through FO-27 may require an isolated type of checkout.  These components  are  checked  as  components  of  a  system during  the  functional  test  of  that  system.    Refer  to  TB 55-4920-328-50 for calibration instructions. 5-6.  Checkout of Temperature Transmitters 11MT15 Through 11MT19. The    five    temperature    transmitters    in    the    water temperature system, (figure FO-7 located in the back of this  manual),  are  mounted  inside  the  data  acquisition assembly  (Unit  11).    These  units  are  identical  and  are interchangeable for checkout and troubleshooting purposes.    Therefore,  the  substitution  method  may  be used   for   troubleshooting   at   the   system   level.      To individually  check  a  suspect  temperature  transmitter,  a dc  millivolt  source  may  be  used  to  provide  an  input signal  to  the  isolated  unit,  and  a  dc  milliammeter  may be used to display the output signal.  The output range of  each  transmitter  is  from  4  to  20  milliamperes  dc  full scale,  depending  on  the  magnitude  of  the  input  signal. To check a suspect transmitter by this method, proceed as follows: a.      Ensure   that   all   METS   electrical   systems   are deenergized. b.  Remove the output leads from transmitter 11MT15 (as an example).  Tag the leads at removal to facilitate installation. c.    Connect  a  dc  millivolt  source  (Honeywell  Model 2720, or equivalent) to 11J8-A and -B, using iron wire to connect to pin A and Constantan wire to connect to pin B.  Observe polarity as shown in figure FO-7. d.  Attach the negative terminal of a dc milliammeter to 11MT5 (+), the positive terminal of the milliammeter to  the  positive  terminal  of  a  24v  dc  power  supply,  and the negative terminal of the power supply to 11MT5 (-). e.        Adjust    the    millivolt    source    for    an    output    of approximately +5.00 mv dc.  Observe the milliammeter for  an  indication  of  approximately  20  ma  dc.    If  the indication  is  approximately  as  specified,  the  transmitter is   not   defective.      If   no   indication   is   noted   on   the milliammeter,  the  unit  is  faulty  and  must  be  replaced. For  information  on  troubleshooting  by  the  substitution method, refer to paragraph 5-25. f.  If the transmitter was found to be usable, reconnect the   removed   wiring,   using   figure   FO-7   as   a   guide. Remove  the  identification  tags  from  the  wires.    If  the transmitter   was   found   to   be   defective,   install   a   new transmitter of like part number.  Then functionally check that    portion    of    the    water    temperature    system    as specified in TB 55-4920-328-50. 5-7.      Checkout   of   Pressure   Transmitters   11MT1 through 11MT14. Four  of  the  14  pressure  transmitters  installed  in  the data acquisition assembly (Unit 11) are strain gage type transmitters   and   may   be   functionally   checked   while isolated  from  the  respective  system.    (See  table  5-1.) Each   strain   gage   type   of   transmitter   utilizes   28v   dc excitation  power  and  provides  an  analog  output  from  0 to   5v   dc.      depending   on   the   magnitude   of   the   inlet pressure.      These   transmitters   are   identified   on   the respective     system     schematics     at     11MT1     through 11MT4.      The   other   10   pressure   transmitters   (11MT5 through 11MT14) are synchronous devices and must be checked as an integral component of the system. 5-8.        Checkout    of    Strain    Gage    Type    Pressure Transmitters 11MT1 and 11MT2. Proceed as follows: NOTE The  instrumentation  range  of  11MT1 and  11MT2  is  listed  as  0  to  250  psia in   table   5-1.      Allowance   has   been made when using pressure equipment  calibrated  in  psig  in  the following instructions . a.    With  all  METS  electrical  systems  de-energized, disconnect  connector  11P1  from  the  mating  connector on 11MT1. b.    Connect  a  jumper  between  11P1-A  and  pin  A  on the  transmitter,  and  connect  a  second  jumper  between 11P1-B  and  pin  B  on  the  transmitter.    (This  action  will provide 28v dc excitation voltage to the transmitter.) c.    Remove  the  dust  plug  from  coupler  11M1  on  the data acquisition assembly.  (See table 5-1.). 5-3