Fisher GEMINI-3 warranty Conductive Trace, Set Up

SEARCHING

7.You are ready to search when the BALANCE knob is adjusted within the 1/8- to 1/4-turn silence (null) space. This is extremely important! If this procedure is not followed correctly, the GEMINI-3 will either constantly give false audio and meter readings (sensitivity too high), or no signals at all (sensitivity too low). The sensitivity will be correctly set and your GEMINI-3 will operate properly only when a 1/4- to 1/8-turn null has been achieved. If you lower or raise your GEMINI-3, you may have to retune by making repeated adjustments to the BALANCE knob and/or the SENSITIVITY control.

Operating

1.Test your GEMINI-3 in an area you are reasonably sure is free of large buried objects. Scatter some metal objects, such as a tool box, piece of pipe.

2. With the instrument properly tuned and held in the hand or suspended by the strap, slowly walk directly toward your test object. Keep the handle as level and steady as possible while in motion or the tuning may change and you’ll receive false signals and/or lose sensitivity.

3. As you approach your target, the speaker sound and meter indication will increase. They will reach maximum readings when you are directly over the conductor (target). Remember, on the GEMINI-3, unlike earlier models, the sound volume and pitch continue to increase after the meter pegs. This allows you to pinpoint without constantly readjusting the SENSITIVITY knob.

4. As you cross the target, the signal indications will begin to decrease because you are moving away. To get a precise fix on the location, make a mark at your feet when readings reach their maximum. Cross over the target, turn around and come back. Make a second mark when readings return to maximum. Your target will be centered between the two marks.

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Gemini-3manual-.ind2 10

TRACING

Operating

1. Once the two starting points have been established and the receiver tuned, walk away from the transmitter in the assumed direction of the buried conductor.

2.Hold the receiver vertically to maintain a peak signal or horizontally, face up, to maintain a null or minimum signal. Either method indicates that you are over the object and tracing its path.

3. As the distance from the transmitter increases, the signal will fade. As this occurs, increase the SENSITIVITY as required.

4.When the signal becomes too weak to trace, stop and move the transmitter closer.

5.Be aware that if you are tracing a pipe, each time a “T” junction or lateral is encountered, the signal will split and weaken.

Conductive Trace

   This is the best method for tracing a single pipe in the presence of other pipes. A portion of the pipe must be exposed in order to energize it by direct connection utilizing the optional Ground Plate Assembly or Ground Rod Assembly.

Set Up

1.If possible, clean the contact point of the pipe with a wire brush.

2.Connect the ground plate clamp to the contact point.

3.Plug the Ground Plate Assembly or Ground Rod Assembly into the transmitter Ground Plate Jack.

4.Set the transmitter on the ground and in an upright position as far away from the contact point as possible, at right angles to the assumed direction of the pipe or cable. Insert the Ground Plate or Ground Rod Assembly in the ground as far away from the transmitter as possible. Lay the Ground Plate flat on paved surfaces. Placing it in a puddle of water and weighing it with a rock will help conductivity.

5.Hold the receiver vertically, in line with the contact point of the pipe at least 30 feet away.

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6/13/06 2:52:52 PM