[MURRAY] HELIUM CONTENT 35 



Summary 



The Shakespear Hydrogen Purity Meter, high and low percentage 

 hydrogen explorers and a Shakespear Permeameter Explorer have 

 been calibrated for use with helium. 



Graphs are given by means of which indicator readings can be 

 converted into percentages of helium. 



It was found : 



(a) that with the Shakespear Hydrogen Purity ' Meter with 

 helium-air, oxygen or nitrogen mixtures about 89-100% helium could 

 be read. 



{b) That with 70-100% hydrogen explorer about 84-100% 

 helium could be read. 



(c) That with a 0-20% hydrogen explorer about 0-30% helium 

 could be read. 



(d) That the permeameter explorer gave 165 mm. deflection at 

 1 mm. distance for 1% helium at about 15-5°C. 



In concluding, we have to acknowledge indebtedness to Dr. 

 G. A. Shakespear for information on the design of the katharometer, 

 and to the Cambridge Scientific Instrument Co., Ltd., for permission 

 to reproduce Plates I and II, and Fig. 1. 



This calibration work was carried out at the Admiralty Physical 

 Laboratory under the direction of Professor J. C. McLennan, F.R.S., 

 Scientific Advisor to the British Admiralty. 

 South Kensington, 



15th April, 1919. 



