BAIRD &TATLOCK (LONDON) LTD. 



Boxwood Head 



FWelain Tub* 



Porcelain Hetd 



.FbrcelainTube 



3 30 to 

 ,1650m. 



Fig. A. Laboratory Fig. B. Thermo-couple 

 pattern thermo-couple. in porcelain tube. 



Fig. c. A method of in- 

 stalling thermo-couples. 



Fig. D. Commercial 

 pattern thermo-couple. 



Fig. E. Bent thermo-couple in steam-pipe. (In this illustration the cast- 

 iron cap which covers and protects the terminals is shown removed.) 



Thermo-Electric Couples. 



For temperatures below 500 C. copper, constantan generally employed and these are usually protected by 

 steel tubes. For higher temperatures it is advisable to use one of the platinum series of thermo-couples which 

 are always protected by porcelain tubes glazed on the outside to prevent gases from coming into contact with 

 and deteriorating the platinum wires. For laboratory work, and in all cases where the temperature is greater 

 than about 750 C., this porcelain tube is the only protection, but for commercial work when the temperature is 

 below about 750 C., a steel protecting sheath is often used outside the porcelain tube. 



(Prices liable to alteration according to market price of platinum.) 



CROSS STREET HATTOTST GARDEN, 



998 



