152 INSTRUMENTATION IN SCIENTIFIC RESEARCH [Chap. 1 



are exposed to different field strengths. This effect causes a variation 

 of the result, depending upon the mass of material contained in the 

 sample. The problem is discussed in detail by Shaw and Elsken. 1 

 With suitable magnetic fields, the maximum error in the deter- 

 mination of humidity can be kept as low as J^O.3 per cent. The 

 requirements for instrumentation and accessory equipment for this 

 method are high. 



1 T. M. Shaw and R. H. Elsken, J. Appl. Physics, 26, 313 (1955). 



