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AGRICULTURAL ENGINEERING 



the power while still allowing it to be used in driving the 

 machine is called a transmission dynamometer. Instru- 

 ments used for measuring the draft of implements in the 

 field are called traction dynamometers. Those which simply 

 indicate by a needle and dial the draft or force required 



Fig. 199. A recording dynamometer as designed by the Agri- 

 cultural Engineering Section of the Iowa Agr. Exp. Station. 



to move the implement are called indicating or direct-reading 

 dynamometers. One provided with rolls of paper operated 

 by clock mechanism or by a wheel in contact with the ground, 

 over which a pencil moves and records the draft, is said to be a 

 recording dynamometer. There are also a few kinds on the 

 market which average the draft over a measured run. 



QUESTIONS 



1. Why is an understanding of the measurement of power im- 

 portant? 



