General Instructions for Using Sondes with Line Locators
Introduction:
Fisher Sondes are manufactured with the highest quality and
durability and will deliver accurate locates with any line locator
set to detect at their frequencies. There are currently 4 models
available: SR-82, SR-81, SR-8.2, and SR-51 that operate at 82.175 KHz,
81.92 KHz, 8.2175 KHz, and 512 Hz respectively. These frequencies
were selected for their peak underground performance when
working in many types of soils and pipe compositions. All sondes
feature a size 3/8 x 16 bolt.
Power:
Fisher Sondes operate with a single AA battery. It is recommended
that Alkaline type batteries be used for longer operation life.
Fisher Sondes are protected against accidental battery reversal.
In addition, a battery can be inserted backwards into the Sonde
when not in use or is left for storage.
To Activate:
1) Insert the AA battery in the direction indicated by the
polarity symbol on the housing.
2) Position the battery clip to make contact with the
battery.
3) Screw the studded endcap securely onto the Sonde
housing.
4) Verify on-status of Sonde. Shake the Sonde to make sure
endcap is secured - tighten further if noise is heard. Turn
locating unit on and make sure it responds to the Sonde.
Operating with Line Locators:
1) Use a non-metallic flex push-rod to slide the Sonde into
the desired pipe.
2) Turn on your locator and select the correct operating
frequency if necessary. 1 2
3) Holding your locator perpendicular to the ground, rotate
it 90 degrees and begin tracing. The “blade” of the
locator will run parallel to the direction of the pipe.
4) As you approach the location of the Sonde you will
notice an increase in audio and signal levels.
5) The LEFT/RIGHT and OVER TARGET signals will indicate the
direction you need to move and when you are directly
over your Sonde.
When operating Fisher TW-7700 or TW-8800 line locators with a
Sonde, you will notice a peak signal reading at three different
locations in line with the Sonde direction. The strongest peak signal
being the center of the Sonde, accompanied with two weaker
signals set at equal distances on each side, and in line with the
Sonde. The presence of three peak signals is normal and is a natural
ocurrence with all Sondes.
Operating with Two-Box Locators:
Fisher’s 81.92kHz Sonde is designed to be used with our industry
leading TW-6, two-box locator. Used properly this Sonde can be
accurately located to depths of approximately 10 feet. When
operating a TW-6 with your Sonde:
1) Switch on your TW-6 receiver.
2) Set your mode selector switch to NORMAL.
3) Set your sensitivity to 7.
4) Carry your receiver perpendicular to the ground facing
the direction of the pipe.
5) As you get closer to the location of the Sonde, you will
notice an increase in audio level and meter movement.
Reduce your sensitivity as needed to maintain a scale
reading of 50. A maximum scale reading is observed
when you are directly over the Sonde.
Operating with Line Locators