used in the water adjacent to the NUWC Oceanographic 

 Research Tower. ^ 



THERMISTOR BEADS 



These thermal sensors are acquired in lots up to 

 a quantity of 1000. They are encapsulated by the manu- 

 facturer in a sealed glass envelope 2 inches long by 1/8 inch 

 in diameter, and have a nominal resistance of 2000 ohms at 

 25°C. Upon delivery to the Center the beads are individually 

 identified with wire labels and suspended in the calibration 

 tank for a resistance determination at two or more temper- 

 atures. An automatic balance resistance bridge* is used 

 for this purpose (fig. 13). On the basis of the data obtained. 



CIMRON 



AUTOMATIC BALANCE 



RESISTANCE BRIDGE 



MANUAL BALANCE 

 RESISTANCE BRIDGE 



PRINTER FOR CIMRON SYSTEM 



STANDARD RESISTOR BANK, 

 10 KQ, 1 KQ, 100 Q, 10 Q 



Figure 13. Resistance bridge for calibrating thermistors. 



26 



^Navy Electronics Laboratory Report 1342, The U.S. Navy Electronics Laboratory' s 



Oceanographic Research Tower, by E. C. LaFond, 22 December 1965 



* CIMRON ohms-preamplifier, Model 6869B and CIMRON voltmeter. Model P9400B 



