Product Manual

ManualsBrandsFisher ManualsPipe and Cable LocatorsTW-6 Pipe and Cable Locator

INDUCTIVE LOCATING (with handle)

Use Inductive Locating when you want to nd metal objects or

locate lost or unknown metal pipes and cables. Walk at a right

angle toward what you assume to be the conductor’s position. As

you near the conductor, the speaker sound and meter indication

will increase. They will reach maximum readings when you are

directly over the conductor. Remember, on the TW-6, unlike

earlier models, the sound volume and pitch increases far higher

than when the meter peaks. This will allow you to do most of your

locating without several readjustments of the Sensitivity knob.

As you cross over, the indications will begin to decrease because

you are moving away. To get a precise x on the location, make

a mark at your feet when readings reach their maximum. Cross

over the pipe, turn around and come back. Make a second mark

when readings return to maximum. Measure between the two

marks and bisect the distance. That is where the conductor is.

To establish the path of a pipe or cable (conductor) move “up”

and “down” the line 15 or 20 feet and locate again. From these

three locations you should be able to draw a straight line (unless

pipe has turned). Careful additional locations may be necessary

if no prints of the area are available.

It may be necessary to reduce sensitivity with the knob when the

pipe or cable is large and/or shallow. If the meter needle has

peaked and sound is at a high level, you will want to bring the

sensitivity down to see the peak of the needle at a point less than

100 as you move in half or quarter steps back and forth to get

your peak reading.

MODES OF OPERATION

LOCATING MANHOLE COVERS, VALVES, TEES AND RISERS

These jobs are best performed in the Inductive Mode using the

handle. To nd a valve, tee or riser, locate the main pipe using any

of the previously discussed methods, then, holding the center of

the handle with the receiver leading (face up), walk alongside the

main pipe. Be sure you’re far enough away from the centerline of

the pipe to have a low or no reading. When you cross the sought

after valve, tee or riser, the meter and speaker will signal a larger

mass of metal indicating the valve. At that point, you can cross

and return over the suspected valve location from 3 or 4 directions

to pinpoint its location.

In the case of the paved-over manhole cover, search systematically

by walking out a grid pattern, each “line” of which should be 4

feet apart. Practice this grid technique with a visible cover so that

you can get the “feel” of it.

LOCATING PIPE WHEN OTHER LINES ARE CLOSE BY

Two methods of Inductive Tracing may be employed. In the rst

method, set the transmitter vertically and parallel to the line to

be traced, approximately three to ve feet from the pipe you’re

tracing and away from the pipe not wanted.

Now, follow normal Inductive Tracing instructions. To locate the

other pipe, move the transmitter to the opposite side, three to ve

feet away from the second pipe. In the second method, set up

the transmitter so that its plane points toward the pipe desired.

This positioning induces a maximum eld in the pipe desired and

a minimum eld in the secondary pipe.

MODES OF OPERATION