Aqua-Tronics S.D.A.D.II User manual

OPERATOR’S MANUAL
Directional Acoustic Detector
S.D.A.D.II
by Aqua-Tronics, Inc.
www.aquatronics.com

FIGURE 1
Electronics Showing Controls 1 through 5
1. On/O󰀨 (Push for On) (Hold ~ 2 sec. for O)
2. RED Direction to fault LED
3. Touch screen Display
4. GREEN Direction to Fault LED
5. Neck Strap “D” ring

1. Acoustic sensitivity control (Pre Set when powered on)
2. Time/Depth information window
3. Logic Trip sensitivity control (Pre Set when powered on)
4. Mode Selection (Time & Depth O󰀨 - Time=Msec. - Depth)
5. Battery Level Indicator
6. Red Direction To Fault Indicator
7. Ballistic Impulse Indicator
8. Green Direction To Fault Indicator
9. Ballistic Impulse Sensitivity Control
10. Reset (Resets Acoustic & Logic Trip to default settings)
11. Bluetooth Headphones Connected
FIGURE 2
More Detail of Electronics Showing 1 through 11

FIGURE 3
Headphones showing 1 through 5
1. This side - right ear
2. Power On/O󰀨
3. Micro USB charge receptacle
4. Volume - Push and hold | Up (+) Down (-)
5. Status Indicator
NOTE: Headphones come paired to the SDAD II electronics unit.
Any Blue Tooth headphone can be paired with the SDAD II by
following the pairing instructions with your aftermarket headphones.
NOTE: Make sure other Blue Tooth devices such as smart watches
or phone ear pieces are not near the SDAD II electronics unit wen
turning headphones on or trying to pair new headphones.

1. Mini USB receptacle
2. On/O󰀨 switch (Hold to ‘ON’ | Hold to ‘OFF’)
3. LED – microphone status
During Charging ------ Solid LED
LED o󰀨 = fully charged.
During Operation ----- Solid = paired to SDAD II
Slow ash = Seeking Electronics
2 quick ashes = pairing mode
4. Cord to microphone. (Red to Red and Green to Green)
Identied by switch color.
NOTE: Microphones supplied with SDAD II are paired and ready to
use. New microphones purchased must be paired prior to use.
FIGURE 4
Wireless Microphone Electronics (Red & Green)
Showing 1 through 4

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OPERATOR’S MANUAL
Directional Acoustic Detector
S.D.A.D.II by Aqua-Tronics, Inc.
TABLE OF CONTENTS
BATTERIES
Microphone Wireless Transmitters.............................................. 2
Headphones ............................................................... 2
Battery Replacement ........................................................ 2
SOUND
GENERAL CHARACTERISTICS ................................................. 3
Sound Traveling in Di󰀨erent Materials ........................................... 3
FACTORS AFFECTING SOUND IN FAULT - LOCATING EFFORTS
Location of the Fault on the Cable .............................................. 4
Soil Types ................................................................. 4
Temperature ............................................................... 4
Asphalt & Concrete Surfaces .................................................. 4
Buried Ducts & Pipes ........................................................ 5
Submarine Cables .......................................................... 5
MICROPHONES
Tri-Pods .................................................................. 6
Earth Probe Spike .......................................................... 6
FOOT PROBES
Tricks and Tips ............................................................. 7
FAULT LOCATION – PROCEDURES AND OPERATIONS
TRACE THE CABLE ROUTE .................................................... 7
FINDING THE GENERAL AREA OF THE FAULT.................................... 7
Ballistic Impulse – How It Works ............................................... 7
QUICK SEARCH WITH BALLISTIC IMPULSE ONLY ................................ 8
Automatic Ballistic Calibration ................................................. 8
LOCATING IN A NETWORK, OR ON A “Y” SPLICE.................................. 9
USING ONE MICROPHONE
Setting the Acoustic Sensitivity Control ..........................................11
FINDING THE EXACT POSITION OF THE FAULT
CONNECTING AND USING TWO MICROPHONES ................................ 12
Setting the Logic Trip Sensitivity .............................................. 13
“ZEROING IN” ON THE FAULT .................................................... 13
VERIFYING THE FAULT’S LOCATION .............................................. 14
WAGON WHEEL - LOCATE FROM OFF TO ONE SIDE................................ 16
DEPTH OF FAULT ............................................................... 17
WATER FILLED VAULTS ......................................................... 18
SERVICE & WARRANTY INFORMATION
Warranty ................................................................. 19
Service .................................................................. 19

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BATTERIES
SDAD II
Electronic receiver (UNIT) uses a rechargeable 9.6 V DC NiMh 4.0 AH battery
Battery level is indicated in upper right corner of LCD display. Four green bars
indicate a fully charged battery. One green bar ashing indicates battery must soon
be charged. Install the connector on the supplied smart universal battery charger to
the back cover of the unit and plug the wall cord into any 100 – 240 AC volt supply
for worldwide use.
The battery charger is set at 1.8 amps and should remain at that setting. A small green
LED on the charger will ash slowly if charger is not plugged into the SDAD II unit.
The red LED will be on during charging. The green LED will be on when the battery
is fully charged. The red LED will ash when the charger recognizes the battery is
damaged or the voltage is below 6 volts.
ATTENTION
Do not store the SDAD II where it is exposed to extremely hot conditions, such as the
window of a vehicle, or direct sunlight on a hot day. The battery could become over
heated. This can reduce battery performance and/or shorten its life.
MICROPHONE WIRELESS TRANSMITTERS ---- RED AND GREEN
A dual mini USB cable is provided to charge the microphone batteries. Plug the USB
cable into the provided 2 port USB wall hub. The mini USB cable plugs are plugged
into the wireless microphone transmitters. The red charge LED will light during charge
cycle and go out when the battery charge is complete.
HEADPHONES
A micro USB charge cable is provided for headphone battery charging. Plug the USB
cable into the two port USB wall hub and the micro USB end into the headphones. A
charging LED is red when charging and will go out when the battery is fully charged.
BATTERY REPLACEMENT
Batteries are not user replaceable. If new batteries are required, please send
instrument to the factory for service.

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SOUND
GENERAL CHARACTERISTICS
Sound is mechanical energy in the form of pressure waves. You cannot see sound
waves, but you can form a mental picture of how sound works by comparing it to
ripples moving out in water when a rock is dropped into a quiet water surface. As the
ripples move away, they lose energy and get smaller. If they strike a solid object, they
reect o󰀨 that object and start traveling back in the direction they came from. Sound
waves act very much like these ripples in the lake. They radiate out in all directions
from the source of the sound. They grow weaker and lose more energy the farther
they travel, and if they bounce o󰀨 objects, they will reect back in the direction they
came from.
Thumpers used to locate cable faults create sound waves which radiate out from the
fault in all directions. When the high voltage thumper pulse reaches the fault and arcs
from the conductor to neutral, it creates an “explosion” which is a rapid ionization of
air. If this occurred in open air, it would sound like a large caliber rie discharging.
Since the explosion caused by the thumper pulse occurs underground, the sound
waves are mu󰀪ed and what the operator will hear most often is a soft “THUMP”. Thus
the name for the high voltage impulse generator = “Thumper”
Many times, the sound of the thump is loud enough in the area of the fault that the
operator can hear it without using equipment to amplify the sound. Sometimes, the
voltage arc at the fault releases enough energy to actually move the soil at ground
level. In these cases, the thump can be felt with the operator’s foot or hand.
SOUND TRAVELING IN DIFFERENT MATERIALS
Sound travels at di󰀨erent speeds and with greater ease or di󰀩culty in di󰀨erent
materials. This can have an e󰀨ect on the operator’s e󰀨orts to locate a cable fault.
1. Speed of Sound and Sound Resistance: Sound waves travel at di󰀨erent
speeds in di󰀨erent materials. In open air, sound travels about 1,100 feet per
second (750 mph). In steel, sound travels at about 16,000 feet per second
(11,000 mph). In general, sound travels faster in hard or dense materials. Sound
waves also travel “easier” and with less loss in dense or hard materials. For
example, sound waves will travel farther in steel than in air before losing enough
energy that they can no longer be heard. For the same reason, sound travels
better in water than it does in air.
2. Sound Reections: Sound waves are reected when they hit any object.
Like ripples on a lake surface reecting o󰀨 a rock or oating object, the ripples
reected will be much smaller than the original wave that hit the rock. Sound
waves traveling through soil will reect o󰀨 building foundations, underground
pipes, sidewalks, or even o󰀨 the cement base of a pad mount transformer.

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3. Sound in Air: Compared to many other materials, air is a very poor conductor
of sound waves, or what we call “sound energy”. Place your ear on a railroad
track and you will hear a train several miles away. Stand up and you will see
the train before you hear it. This is the reason deep snow can be a problem to
a cable fault.
FACTORS AFFECTING SOUND IN FAULT-LOCATING EFFORT
LOCATION OF THE FAULT ON THE CABLE
1. Fault on top of the cable. An easy fault to locate as all of the thumpers energy
is coming straight up. You can normally hear this type without a listening device.
Most of the time you can feel the pressure wave with your foot or hand.
2. Fault on the bottom of the cable. This fault is sometimes hard to hear because
the thumpers pressure wave goes down and reects back up, much of the
energy is lost in the soil at the point of reecting.
3. Fault on the side of the cable and the thump is arcing into another cable
phase. The cable on the side will absorb most of the energy and very little of the
sound wave is available to the operator. The operator will not be able to hear the
thump without a good acoustical instrument of some type.
SOIL TYPES
Some types of soil can mu󰀪e the sound created by the “thump” more than other
types. Dry, porous soil like sand is a good example. Even though grains of sand by
themselves are dense and would be good conductors of sound if they were packed
together, sand is lled with tiny air pockets that are poor conductors of sound. After a
rain storm, the tiny pockets are lled with moisture and the overall sound conducting
ability will improve.
TEMPERATURE
Frozen soil is generally quite easy to locate in because the ground is quite hard
with ice frozen around the grains of soil and ice is a very good conductor of sound,
however this is not always the case. Repeated freezing and thawing can create air
pockets due to soil’s movement during the freezing and thawing process.
ASPHALT & CONCRETE SURFACES
How well a thump sound can be heard above an asphalt or concrete surface depends
on how rm this material is in contact with the soil, or how much air space is between
the soil and bottom side of the material the microphone is set on. Dead air spaces can
be created under these surfaces by soil settling or by soil surface movement caused
by freezing and thawing.

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BURIED DUCTS & PIPES
Because sound travels best along the path of least resistance, a duct will act like a
rie barrel. Instead of the sound going out in all directions, most of it will travel in both
directions and emerge at both ends of the duct.
In a quiet area where there is almost no back ground noise, try listening for the thump
over the route of the cable if it’s in a duct. IF THE BACK GROUND NOISE EXCEEDS
THE SOUND OF THE THUMP, YOU WILL NOT BE ABLE TO HEAR THE THUMP.
If it is a quiet area, higher acoustic sensitivity and logic trip can be attempted. The
settings explained later are for normal areas that do have some back ground noise.
The operator will know because of false tripping if the controls are set higher than
they should be for the area being searched.
SUBMARINE CABLES
Sound travels well in water with very little amplitude loss, so a thump can be heard
a great distance from the fault with a microphone placed below the water surface. If
the microphone is placed above the surface, no sound will be heard. When the sound
wave changes from water to air, the surface cannot vibrate or reproduce the noise.
Fault locating submarine cables in a small lake are normally very easy because a
lake does not have a current (water ow) passing by the microphone. The friction of
the water moving over a microphone can create loud noises to the operator. Water is
such a good conductor of sound and has so little loss in amplitude; the loudest sound
will be hard to pin-point. A two microphone directional system makes this easy.
A frozen lake can be a problem unless two microphones are used. When the sound of
the thump comes up from the cable and strikes the ice, the ice cover will act as a kettle
drum and the entire frozen surface will have the same amplitude. This is also true for
underwater microphone use. The sound can be heard from a great distance but the
operator will not be able to hear the di󰀨erence in amplitude. Using two microphones
that can produce direction that is not dependent on amplitude must be used.
SPECIAL MICROPHONES ARE AVAILABLE FROM THE FACTORY FOR
SUBMARINE CABLE FAULT LOCATING. THE STANDARD MICROPHONES
SUPPLIED WITH SDAD II WILL BE DAMAGED IF THEY ARE PLACED UNDER
WATER.

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MICROPHONES
TRI-PODS
When a sound wave hits a hard surface like a sidewalk or driveway, the sound
wave reects o󰀨 and is much smaller than the initial wave. The di󰀨erence in the
two waves is transferred to the hard surface. The hard surface is now acting like the
old phonograph record and an electronic pick up can be set on the surface that will
reproduce the sound. Connect a microphone to a tri-pod using a 10 inch extension
tube and stand it on the hard surface. The energy or vibration in the hard surface will
activate the microphone so the thump can be heard.
NOTE: Background noise can be a problem when working over asphalt or
concrete. In some cases this can hide or mask the sound of the “thump”.
NOTE: Tri-Pods do not work well in soft soil conditions. Pushing one or more
of the tri-pods legs into the soil can sometimes work well enough that the earth
spikes are not needed.
EARTH PROBE SPIKE
To solve the types of problems encountered with Tri-Pods on surfaces that are not
solid, Aqua-Tronics developed the Earth Probe Microphone Spike for use in soil,
water, snow and other soft materials. By inserting the metal spike through the surface
skin, or top layer of soil, sound waves from the thump can be detected before they
have a chance to reect from the soil surface, or disperse into the air.
Earth probe microphone spikes also eliminate many background noise problems.
Sound waves originating at the cable fault travel directly through the soil to the earth
probe microphone spike. Because they greatly reduce background noise, the earth
probe microphone spike should be used when possible. If a cable route lies under a
sidewalk, using an earth probe microphone spike o󰀨 to one side of the sidewalk will
allow the operator to hear the thump more clearly.
FOOT PROBES
EARTH PROBE MICROPHONES ARE NOT LAWN DARTS AND SHOULD NEVER
BE DRIVEN OR FORCED INTO HARD SOIL, OR FROZEN GROUND.
Cantilever damaged can occur where the earth probe spike screws into the
microphone bulb if the earth probe is not being inserted into the soil in a vertical
(straight up and down) direction. Damage can also take place if the earth probe spike
is not screwed up solid to the electronic bulb.
To eliminate the above possibilities, a unique foot probe has been developed to use
with the earth probe microphones. The operator can push the microphone into the
ground with his/her foot, using as much force as needed without placing undo stress
on the microphone bulb.
NOTE: Hammerhead probes are available for extreme soil conditions.

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TRICKS AND TIPS
a. Wind problems: Try placing the microphone inside a tra󰀩c cone.
b. Hard ground too hard for any kind of spike insertion. Carry a cordless drill and
drill a 3/8 hole in the ground. Insert the microphone spike in the hole.
c. The cable was under dirt and now it’s under concrete and its two miles back to
the truck for tri-pods. Set the electronics down on the concrete. Place the metal
tip of the microphone spike on the concrete with the microphone handle resting
on the electronics. Let go of the microphone and listen. If the thump can be
heard, set the second microphone down in the same manner, over the route of
the cable, but in the opposite direction. This will provide 30 inches of separation
of the two microphone tips and by not touching either microphone, the only
vibration they pick up should be the thump. If they are used correctly, the earth
probe microphone can be used on hard surfaces.
FAULT LOCATION – PROCEDURES AND OPERATION
TRACE THE CABLE ROUTE!
Before the fault locate can begin, the route of the cable must be located and marked.
While tracing the route of the cable, watch for signs of construction or digging near
the route. This could be an indication of where the cable fault is located.
FINDING THE GENERAL AREA OF THE FAULT
There are two methods that can be used to nd the general area of the fault.
a. The ballistic impulse level drop o󰀨.
b. Using one microphone to listen for the thump.
In either case, the ballistic impulse level indicator plays an important role.
BALLISTIC IMPULSE --- HOW IT WORKS
The ballistic impulse level indicator allows the operator to “see” the output pulse from
the thumper as it travels down the cable route. The indicator provides a “reference
signal” each time the thumper pulse occurs. It also provides the rate at which the
thumper is pulsing the cable.
The ballistic impulse circuitry is independent from the acoustic circuitry. The
headphone and microphones are not needed for the ”Quick Search with Ballistic
Impulse Only” as listed in the following section of this manual.
When the thump pulse arrives at the fault, the voltage will arc to the neutral. Most
of the current at the fault will return to the thumper, but not all of it. A small portion
will be lost in the soil around the fault and a small portion will travel to the far end
neutral ground rod connection. Most of the current is between the cable fault and
the thumper. A large magnetic wave will be between the cable fault and the thumper

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ground rod. A small magnetic wave will be between the cable fault and the ground
rod at the far end of the cable. AS A RESULT, THE OPERATOR SHOULD SEE A
REDUCTION OR COMPLETE LOSS IN BALLISTIC IMPULSE LEVEL WHEN THE
FAULT HAS BEEN PASSED.
NOTE: Isolating the neutral at the far end of the cable on a jacketed primary will
remove that current path and the magnetic fall o󰀨 will be much more abrupt at
the fault. Isolating the far end ground rod on a direct buried (NON-JACKETED)
primary may help, but because the neutral is still in contact with the soil the fall
o󰀨 may not be as abrupt.
QUICK SEARCH WITH BALLISTIC IMPULSE ONLY
AUTOMATIC BALLISTIC CALIBRATION
1. Move 20 feet away from the thumper and 5 to 10 feet o󰀨 to one side of the
marked cable path. Turn on the SDAD II electronics. See Figure 5
2. Start thumping the cable.
3. After about 3 or 4 thumps, the ballistic impulse level will automatically set.
4. Walk the cable path maintaining the same approximate 5 to 10 feet distance
from the cable path. The ballistic impulse reading will be lost after passing the
cable fault. Mark this location.
5. Continue down the cable path 30 to 40 feet. If the ballistic impulse level does not
return, a microphone placed at the pre-located spot and is usually close enough
to hear the thump.
Figure 5

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If the ballistic impulse returns at some short distance past the pre-located spot, the
spot marked may not be the cable fault. A ground rod at a cable junction, a cathodic
anode, or any kind of tie point can break up the magnetic wave in the area of
connection. An open neutral can also break up the magnetic wave in the area of the
open. If the signal comes back, keep moving down the route. When the real fault has
been passed, the ballistic impulse will not come back to its original level.
NOTE: This same method of pre-locating can be made from inside a vehicle
as long as the same distance from the cable path can be maintained. The
electronics can be set on the seat, or held out the window and then repeat
steps 1 through 5.
TO RE-ENTER BALLISTICS AUTOMATIC CALIBRATION MODE, TURN THE
SDAD II ELECTRONICS OFF AND BACK ON.
The above pre-location method can be conducted at greater distances from the cable
route as long as that distance is maintained throughout the ballistic search, however
a manual setting of the ballistic impulse sensitivity control will be necessary at greater
distances from the cable route.
NOTE: Never set up a magnetic adjustment or a ballistic search directly over
the cable path. This can only be accomplished if the operator is o󰀨 to one side
of the cable path.
LOCATING IN A NETWORK, OR ON A “Y” SPLICE
With all of the conductors on one feed isolated. The thumper pulse can only travel
in the conductor between the thumper and the cable fault. As a result, the magnetic
wave (ballistic impulse) can only be in the cable between the thumper and the cable
fault.
Walk or drive the cable route. If the magnetic wave is lost when a vault has been
passed, go back to the vault and travel that portion of the cable where the magnetic
wave is present. Keep in mind that magnetic waves are broken up around ground
rods and tie points so move past the vault 30 to 40 feet before the determination is
made that the magnetic wave is not in this portion of the cable.

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USING ONE MICROPHONE
Once the general area of the fault has been located using ballistic impulse, it is time
to us a microphone.
1. Connect one microphone. Turn on the microphone being used (red or green)
See Figure 6. The ‘Time/Depth information window’ will show that channel as
“ON” when that microphone is connected to the electronics.
2. Since direction to fault will require two microphones, the second microphone
needs to be with the operator during the search. Keep that channel turned o󰀨
until that microphone is needed.
3. Blue Tooth headphones will aid in hearing weak thump sounds.
Figure 6

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SETTING THE ACOUSTIC SENSITIVITY CONTROL
The acoustic sensitivity control is pre-set at power on. This setting can be used on the
majority of cable faults. Touching any of the controls on the LCD will take the user to
the adjustment screen. See Figure 7. The user can increase or decrease any of the
SDAD II parameters from the default settings. To return to the default settings, touch
the reset button above the acoustic sensitivity control on the main screen.
See Figure 6.
The LCD should read “TIME/DEPTH OFF”. In this mode, direction to the fault using
two microphones can be achieved; however background noise could provide false
tripping.
In general, the lower acoustic (sound) sensitivity that can be used, the less background
noise will be present during the fault locate. Until the actual “THUMP” is heard and
the direction to fault is needed with a second microphone installed, the acoustic
sensitivity control can be set to “MAXIMUM”.
With one microphone in place, listen for the “THUMP”. Once a “thump” can be heard
at the same time the ballistic impulse indicator indicates a thump pulse has taken
place, push the “MODE” button. The ‘Time/Depth information window’ should now
read “TIME = ---MSEC”. See Figure 8.
The next ballistic impulse passing the instrument will turn on a clock. When the thump
is heard, the clock will turn o󰀨 and a time to fault will be displayed in the ‘Time/Depth
information window’. If the microphone is moved in either direction over the route
of the cable, the next “thump” will display a shorter or longer time depending on the
proximity of the microphone to the fault at the new listening spot.
In the “TIME = ---MSEC” mode, the ballistic impulse must be present to activate a
Figure 7

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time to fault. This will greatly reduce false time indication due to random background
noise. A constant background noise could still create problems when the ballistic
impulse is passing by.
As you get closer to the fault, the thump will get louder. Turn down the acoustic
sensitivity control. When the sensitivity control can be reduced to a 16 or less on the
control dial and the thump can still be heard, a second microphone can now be used.
FINDING THE EXACT POSITION OF THE FAULT
CONNECTING AND USING TWO MICROPHONES
a. Connect the second microphone to the electronics by turning the microphone
electronics on. See Figure 8.
b. The RED microphone connects to the red LED on the right side of the display
screen and the GREEN microphone will connect to the green LED on the left
side of the display.
c. The ‘Time/Depth information window’ should show both channels “ON”
d. Set both microphones over the route of the cable.
If earth probe microphone spikes are being used in dirt, sand, snow, etc… they
should be separated 24” or more during use. If Tri-Pods are being used on a hard
surface like concrete or asphalt, they should be separated 30” or more during use.
With experience, the operator may nd that microphones can be placed much closer
together than indicated. Until the operator is familiar enough with the instrument to
know where the limitations are in di󰀨erent soil or ground conditions in his/her area, it
is recommended that the suggested microphone spacing be followed.
Figure 8

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SETTING THE LOGIC TRIP SENSITIVITY
The logic trip sensitivity control is pre-set at power on. This setting can be used on the
majority of cable faults. Touching any of the controls on the LCD will take the user to
the adjustment screen. See Figure 9.
The user can increase or decrease any of the SDAD II Parameters from the default
settings. To return to the default settings, touch the reset button above the acoustic
sensitivity control on the main screen.
“ZEROING IN” ON THE FAULT
When a direction to fault LED lights up at the same time a ballistic impulse indicator
indicates a “thump” has taken place, a time will be displayed in the “TIME/DEPTH”
information window if the instrument mode has been set to “TIME =---MSC”. This
number is clocked from when the “thump” pulse passed the instrument and the rst
microphone heard the sound.
If the Time displayed is a large number, the operator can move the microphones 10
to 15 feet for a new reading. If the LCD time is a small number, the fault is very close
and the movement of the microphones should be a very short distance. This will vary
greatly depending on the locating conditions. The distance to move microphones will
become easier and more exact with experience.
When the direction to fault LED indicates the fault to be in the reverse direction, the
fault has been passed and the operator needs to reverse his/her direction. Move
both microphones in the reverse direction the same approximate distance as the
microphones are separated. (If the microphones are 24 inches apart, move both
microphones 24 inches in the reverse direction) This will keep the operator from leap-
frogging over the fault. Make these movements until once again; direction to fault
LED indicates a reversal in direction.
Figure 9

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The trailing microphone is near the fault and should be left were it is. Move the lead
microphone back ¼ inch at a time. When both directions to fault LED’s light up, the
fault is centered between the two microphones. This spot is called the “NULL”
The fault is equal distance from each microphone, but this could be o󰀨 to one side of
the cable route.
VERIFYING THE FAULT’S LOCATION
The nal step needed to verify the fault location is the “90 degree WALK AROUND”.
Keep in mind that “DEAD INCH” accuracy can only be obtained if the “NULL” reading
is found in both the IN-LINE locate and the ACROSS THE CABLE locate. See Figure
10.
One microphone is placed directly over the “NULL” point or position of the fault. This
microphone will be called the PIVOT MICROPHONE. Move the other microphone
around the pivot microphone and take four ( 4 ) readings.
a. 30” up the cable route.
b. 30” down the cable route.
c. 30” o󰀨 to one side of the cable route.
d. 30” o󰀨 to the other side of the cable route.
This will provide readings on all four sides of the fault at 90 degree intervals. The
direction to the fault LED will show which microphone received the thump rst.
Figure 10
What was thought to
be the cable route
What was thought to
be the cable fault
Where microphones
were placed for 90°
walk around

15
If the cable route was o󰀨 to one side of where the operator thought it was, the pivot
microphone would not prove all four readings. Moving the microphones in the new
direction until a “NULL” point is found will require the 90 degree readings to be taken
again because a new spot was found for the pivot microphone. See Figure 11.
THE LED FOR THE PIVOT MICROPHONE WILL LIGHT AT EACH OF THE FOUR
READINGS IF THE FAULT IS UNDER THE PIVOT MICROPHONE ON THE 90
DEGREE WALK AROUND.
Figure 11
What was thought to
be the cable route
Actual cable route
CORRECT
INCORRECT
Actual cable fault
What was thought to
be the cable fault
Where microphones
were placed for 90°
walk around