next up previous contents index
Next: B.2 Selected FCS Power Up: B. Conversion Algorithms for Previous: B. Conversion Algorithms for

Subsections


B.1 Temperature Sensors


Detector temperature

To convert ERD voltage to actual detector temperature one should apply the following relationship:


\begin{displaymath} T = B \frac {1} {~^{10}{\rm log}(R_s)+ {\frac {K} {~^{10}{\rm log}(R_s)}} - A}~~~~~~~[{\rm K}] \end{displaymath} (B.1)

where: 


  A, B, K = constants, different for each sensor

  $R_s$ = sensor resistance in $\Omega$, according to


\begin{displaymath} {\rm\frac{R_s}{1000} = \frac{1}{\frac{1}{C_1 {\times} tmd - C_2}-\frac{1}{R_p}} -R_k}~~~~~~~~[\Omega] \end{displaymath} (B.2)

Where: 


  tmd = telemetry data value

  $C_1, C_2$ = constants

  $R_k$ = harness resistance in k${\Omega}$

  $R_p$ = EEU shunt resistor in parallel to sensor in k${\Omega}$


Table B.1: Constants for PHT temperature sensors.
Sensor A B K
FCS1 6.54 2.90 10.67
FCS2 6.54 2.90 10.67
C100 5.44 3.05 7.34
C200 4.51 3.12 4.92
P1 6.02 3.61 8.77
P2 7.59 3.13 14.40
P3 5.11 3.49 6.29
S1 6.54 2.94 10.66
S2 6.54 2.90 10.67


Table B.2: Resistances for PHT temperature sensors.
Sensor $C_1$ [k$\Omega$] $C_2$ [k$\Omega$] $R_k$ [k$\Omega$] $R_p$ [k$\Omega$]
FCS1 0.259 495.83 1.12 1000
FCS2 0.256 495.83 1.12 1000
C100 0.099 146.38 1.34 infinite
C200 0.048 $-$78.32 0.67 infinite
P1 0.174 344.55 1.12 499
P2 0.210 388.13 1.34 499
P3 0.182 288.11 1.34 infinite
S1 0.173 341.63 1.12 499
S2 0.170 336.88 1.12 499


EEU temperature


\begin{displaymath} T = \frac{B}{A+ln(R_s)} ~~~~~~~~~~~~~~~~~~[{\rm K}] \end{displaymath} (B.3)

with


\begin{displaymath} R_s = \frac{tmd-2048}{4096-tmd} \times 7500~~~~~~~~~~~~~~~~~~~[\Omega] \end{displaymath} (B.4)

where 


A =	3.9489
B =	3442 K
R$_s$ =    sensor resistance in $\Omega$
T =	EEU Temperature in K
tmd =	telemetry data value

next up previous contents index
Next: B.2 Selected FCS Power Up: B. Conversion Algorithms for Previous: B. Conversion Algorithms for
ISO Handbook Volume IV (PHT), Version 2.0.1, SAI/1999-069/Dc