(A) Growth Sensor 
9.5 mv O-9 mv 
Signal 
to Recorder 
+ 
(B) Voltage Regulator 
+ ‘ 
lOV dec 
Input 
Parts List 
1-Rs 78.7—ohm, Ohmite, Type 884, 3-watt fixed resistor. 
2-R, 976-ohm, Ohmite, Type 884, 3-watt fixed resistor. Approx. 
3-R; 1,500-ohm, Ohmite, Type 884, 3-watt fixed resistor. 
4-R,,R, 100-ohm variable resistor, IRC Circuit- Trim, No. 400-10. — 9.5 mv aa 
5-R3 Slidewire, Karma No. 431 Alloy resistance wire, B& S Output 
31, 10.09 ohm/foot. Driver Harris Co., Harrison, N. J. 
6-Z, 5.6-v. Zener diode, IRC 1 ZM 5.6 T5, 1 watt. | i 
z/ Connecting wires to slidewire disk, Belden No. 8430-25 | | 
phonopickup wire. | | 
* We chose this type of resistor because of its low temperature coefficient of + 20 RYE ohm Load 
fo} 
p.p.m./ C. IRC, Type AS, or Aerovox Aeromet, Type CPFX, would also have been 
suitable. A 1/2-watt power rating would have been adequate in place of the 3-watt (3, 9 ohm Sensors 
rating used. in Parallel) 
Figure 7.—Schematic diagrams and parts list of (A) growth sensor shown in figure 3; and (B) voltage regulator. 
