Due to the many factors affecting the generation of LF 

 signals a graph of gain setting vs. rope size and con- 

 struction is of little use. The LF gain setting will 

 depend on the rope size, construction, and its state of 

 wear. Section 4.5.2 sets out general 'rules of thumb' 

 which should be followed to gain the most information 

 from the LF trace. 





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Fig. 4.9 1 1/8" 6x27 Hoisting Rope 



4.5.2 LF Gain Potentiometer Setting 



On ropes with very little wear the LF Gain should be ad- 

 justed to show + 3 small divisions of signal on the chart 

 recorder. This will allow significant local faults to 

 be quite visible. With rope wear this initial setting 

 will cause the LF trace to go off scale in sections where 

 corrosion and wear are heavy. The gain should be reduced 

 to ensure that these areas are mostly on the chart so 

 that only occasional peaks go off the chart limit. 



A-31 



