12 
Rs Re, Reps Rez Res Res 
| 
S re! | 
| S2do S3 S4 9 35 Oe SG So 
R, oni b 
l R 
I! 2 
fe a 
I 
I 
| 
es Sh 
E= 8.1 volts CABLES Py iss 
R,= 30K COURSE ZERO ADv. alr Vee 
Roe SAK 
R3= 5000 FINE ZERO ADJ. PRESSURE Sey 
R¥= 5002 FINE ZERO ADu. TRANSDUCER Fs | Rg 
Rej= 392,1002 (25 ft. CAL). 
Rep = 196, 980 2(50ft. CAL.) 
Re3= 97,905 2(100ft. CAL) 
Req = 65, 211 2 (150 ft. CAL.) 
Res = 48,8652 (200 ft. CAL.) 
S,= OFF-ON SWITCH 
So- Sg= MOMENTARY SWITCHES 
R= TEMPERATURE SENSITIVE RESISTORS 
Figure 6. Depth bridge for data system 
chosen are shown in the diagram for the remaining calibrate 
resistors. 
A convenient laboratory method for determining the voltage 
output, €,, as a function of depth is to expose the transducer to 
atmospheric pressure, which provides a sufficiently stable ref- 
erence point, zero the bridge, and then measure g, as the individ- 
ual calibrate resistors are inserted. These resistors can also be 
used to make calibrations for sensitivity in the field; however, 
these calibrations should be made when the ship is at zero bubble 
and maintaining depth well. 
Mercury batteries (Mallory type TR-136R) were also used in 
the depth circuits; they had a no-load voltage of 8.10 volts. A mod- 
ification (not shown) of this basic bridge was made for use with 
