DESCRIPT ION 



Fig.l shows the MT-75 DC Rope Tester with Headphones attached. 

 The tester assembly including headphones is stored in a compact 

 Carrying Case (not shown) . 



In operation, the Tester Assembly attaches to the rope by means 

 of guide shoes to detect flaws as the rope moves at rates from 

 5 fpm to high speeds of 500 fpm. Rope flaws are indicated by 

 clicking sounds in the Headphones. The fault signal can also be 

 recorded by a strip chart recorder or a cassette recorder. Differ- 

 ent rope flaws can then be identified from their characteristic 

 chart patterns. 



The Rope Tester operates from replaceable or rechargeable 

 9 V batteries. 



FUNCTION OF SIGNAL CONDITIONING CIRCUITS 



Fig. 2 shows a Functional Block Diagram of the instrument. The 

 signal conditioning circuitry comprises the following components: 



1. PREAMPLIFIER AND SPEED COMPENSATION CIRCUIT - This circuit 

 amplifies the sense coil signal. At the same time, it equa- 

 lizes the signal to make its amplitude independent of rope 

 test speed (at speeds greater than 5 fpm) . 



2. DETECTION LEVEL CIRCUIT - This circuit controls the threshold 

 level at which fault signals are detected. 



3. SIGNAL ENHANCER CIRCUIT - This circuit controls the extent 

 to which that part of the test signal above the detection 

 level is enhanced and that part below the detection level is 

 suppressed. 



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