Device matches ends of a buried conduit, transversing an inaccessible area, without cutting the current

Peck, R. R.

English

NASA Technical Reports Server

September 1969
	 Brief 69-10347 
Tracer of Electrical Conduit or Pipes
3ouJ 
Receptacle 
Transistor 
Amplifier
Battery	
-i 
H 1 I 1 -
Th1x 
Diode	 Diode 
	
Transistor	 Transistor 
	
I Amplifier	 L -	 Amplifier 
L________ -------
High-Speed
Switching Circuit

(Shown as Relay Circuit to Illustrate Action( 
Fig. 1. Operation of the Device 
The problem:	 How it's done: 
Development of a simple method for identifying
	 Two transducers A and B, linked to a small bat-
the two ends of a conduit (or pipe), traversing an
	 tery-powered unit (Fig. I), are clipped about 1 foot 
inaccessible area, without cutting of the current,
	 apart on the initial length of each conduit in turn 
The solution:	 near the power panel, B being closer to the panel 
A novel device (Fig. I) matches the ends of a
	 than is A. A small battery-powered sounder is set on 
buried line quickly and easily.
	 the final end of the conduit, near the receptacle. 
(continued over(eat) 
This document was prepared under the sponsorship of the National 	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States
	 will be free from privately owned rights.
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When A and B are clipped to the right conduit the 
signal from the hammer reaches A (1 foot from B) 
60 iisec before it reaches B. The signal from trans-
ducer A is amplified and rectified and closes circuit 
X; at this point the battery sends a signal to the in-
dicating device. Sixty microseconds later the B pulse 
opens circuit Y. When each sound wave ceases (after 
each hammer strike), circuit Y closes. The integrator 
accumulates the pulses and gives a steady reading on 
the meter when both ends of one conduit are tapped. 
Any metal pipe or duct may be traced in this way. 
Bursts of audiotone may be used instead of a hammer.
Note: 
This Tech Brief is complete in itself. No addi-
tional information is available. 
Patent status: 
No patent action is contemplated by NASA. 
Source: R. R. Peck of 
North American Rockwell Corporation 
under contract to 
Manned Spacecraft Center 
(MSC-15223)
. 
Brief 69-10347	 Category 01


Tracer of electrical conduit or pipes

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