Appendix 5 



Circuit diagram and list of components required to construct the arc-welder unit 

 for welding thermocouple psychrometers . 



Quantity 



1. Battery, 45 volt (i.e., Eveready No. 762-S) 1 



2. Resistors 



a. 250 ohm, 5% 1 



b. 50 ohm, 1 turn, potentiometer 1 



3. Capacitor, 60 uf 1 



(For convenience the unit can be housed in an aluminum box.) 



carbon 

 rod 



60>jf 



250 



n 



son 



45v 



26 



