Fisher TW-82P Operating Manual

TW-82

DIGITAL LINE TRACER

WITH PASSIVE POWER DETECTION

P

Operating Manual

Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176

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CONTENTS

Introduction ....................................................................... 3

Contents

Transmitter

Inductive Locating

Conductive Locating

Receiver

Control Panel

Standard Mode

Lateral Mode

Passive Power Mode

Auto Power-Down Receiver

Metric/Imperial Unit of Measure

................................................................................4

.................................................................... 5-7

.....................................................7

..................................................7

......................................................................... 8-17

...............................................................8

....................................................... 9-11

......................................................... 12-14

Lateral Tracing Operation

Lateral Mode Programming

............................................ 14-16

............................... 13

............................ 13

.................................... 17

.......................... 17

Specifications

Accessories

2

.................................................................. 18

......................................................... Back page

INTRODUCTION

The TW-82P Digital Line Tracer components include a
Transmitter, Receiver and Ground-Rod Assembly.

The TW-82P is an active single-frequency and passive power

current line tracer that is used to locate and trace buried

utilities using any of the following four tracing methods:

1. Conductive Method. With this method, the Transmitter
energizes the buried utility by making a direct electrical
connection to it with Conductive Tracing Cables. In most
cases, this method generates the strongest magnetic eld for
the Receiver to detect above ground.

2. Inductive Method. When a direct physical connection

to the utility is unavailable, the utility may be energized
indirectly by magnetically coupling an energizing current
from the Transmitter. Some prior knowledge of the utility’s
location is required so that the Transmitter can be placed
and oriented, on the ground, near the utility in the most

effective manner.

3. Coupling. In some cases a utility may be exposed, but
does not provide a direct connection for the conductive
tracing cables. The optional accessory coupling clamp can be
clamped around the exposed utility to magnetically couple

an energizing current from the Transmitter into the utility.

4. Passive Power. 50Hz and 60Hz electric current ows on

underground power lines and also on underground utilities

that are not power lines. In Passive Power Mode, the TW-82P
can detect this electric current using the Receiver as a stand-

alone instrument without need for a transmitter.

Never make direct contact with electrical or communication
lines that are in service. To trace such lines in service,

perform an inductive trace, either with or without the

coupling clamp.

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3

CONTENTS

Carrying Case

Ground-Rod Assembly

(Ground-Rod & Conductive Tracing Cables)

Transmitter

Operator’s Manual

4

Receiver

6 D-cell Batteries

Calibration Certificate

TW-82P TRANSMITTER

TW-82P Transmitter

The Transmitter has two controls: & .
The button has a dual function:

1. When the Transmitter is powered on, switches
the device between normal (1/4 watt) and high (1.0 watt)

output.

2. With the Transmitter powered off:

A. Press-and-hold to program the Auto
Power-Down feature.

Successive presses of will show a ashing
battery indicator, followed by a blank screen or the

illuminated battery indicator.

• An illuminated battery indicator means

Auto Power-Down is activated.

• A blank screen means Auto Power-Down

is deactivated.

B. After you release , the transmitter

power will turn on.

With the Auto Power-Down feature activated, the

Transmitter will automatically turn off 60 minutes after

the last key-pad press by the user. This is a battery
saving feature. The Transmitter will warn of power-down

by switching ON and OFF as described on the top of the

following page.

5

TW-82P TRANSMITTER

Low Battery Power-Down Warning

When the Transmitter batteries are near the end of their

useful life, the Transmitter will warn the operator before

shutting down.

Five minutes before shutting down, the Transmitter will

alternately stop and start transmitting at approximately one-

second intervals. The operator using the Receiver, even at a
distance from the Transmitter, will notice the signal turning

on and off before the power turns off completely.

Accessory Output

1. Flip up the black protective cover to expose the

Accessory Output Jack.

2. Connect the conductive tracing cable plug for conductive

tracing.

When the conductive tracing cable is connected, Signal
Current will be displayed. The Signal Current Bar Graph
shows the quality of the connection.

Vertical Bars will illuminate to indicate the current
as follows:

mA indication 1 2 4 8 15 25 50 100 200
Actual Range (mA)

0.5-1.4 1.5-2.9 3.0-5.9 6.0-12.9 13.0-18.9 20.0-39.9 40.0-74.9 74-149 150+

Automatic Load Impedance Matching adjusts output to
provide full rated power over a wide range of loads (e.g.
utility types and conditions). It is tolerant of both dry
(high resistance) and shunted (low resistance) ground

connections.

The Transmitter has a built-in antenna for inductive

locating. When the Cable Jack is not connected, the inductive

antenna automatically engages and begins transmitting.

When locating inductively, the Signal Current Bar Graph
will not be displayed, as there is no conductive trace load to

be measured.

WARNING: Do not handle output leads unless power is off.
ELECTRIC SHOCK HAZARD: Servicing to be performed

by qualied personnel only.

NEVER connect conductive cables to an energized power

line.

6

TW-82P TRANSMITTER

INDUCTIVE LOCATING

Inductive locating is most effective with

the Transmitter straddling the utility as

illustrated, with the utility perpendicular to the
Transmitter’s batteries.

If the utility direction is unknown, place
Transmitter on the ground, power on,
and sweep the Receiver a complete
360º around the Transmitter, keeping
at least a 25-foot (8-meter) distance
between the Transmitter and Receiver.
If unsuccessful, move the Transmitter
to another location. When located, the
Receiver’s azimuth indicator will show the

direction of the utility.

In inductive mode, the Transmitter’s LCD
will not display Signal Current. When the
conductive tracing cables are plugged in, the
Signal Current display will illuminate.

CONDUCTIVE LOCATING

1. Place the Transmitter on the
ground and turn it off.

2. Connect the Conductive Tracing
Cables to the Transmitter.

3. Push the Ground Rod into
the earth at a 90º angle to the

direction of the utility.

4. Connect the red clamp to the non­energized utility.

5. Connect the black clamp to the Ground Rod.
Be sure not to place the wires over any other

utility.

6. Turn Transmitter On.

7. With Receiver in hand, move at least 25 feet
(8 meters) away from the connection point.

8. Sweep the Receiver in a circle around the

connection point.

9. Using information provided on the display,
nd the areas that need to be traced and analyze the
situation in more detail to nd the buried utility.

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7

TW-82P RECEIVER

TW-82P Receiver

CONTROL PANEL

1. Press-and-Hold to turn ON.

2. Press-and-Hold to turn OFF.

3. Choose Metric/Imperial unit of measure (see instruction p17).

Press to select volume settings

• In Standard and Lateral Modes, tap
the button to adjust volume:

1. Mute 3. Medium Volume

2. Low Volume 4. High Volume

• In Passive Power Mode, no mute is available.
Only volume settings 2, 3 & 4 are available.

Press to select from any of 3 modes

Standard Lateral Passive Power

Adjust GAIN in Passive Power Mode

These keypads have no function in the Standard or

Lateral Modes.

8

TW-82P RECEIVER

STANDARD MODE

In this default conguration, the TW82P Receiver requires no

operator intervention to trace a line under most circumstances.

Only the volume can be adjusted in this mode.

The following values & conditions are displayed on the LCD display
in Standard Mode:

- Signal Strength

- Left/Right & Over-Target

- Azimuth

- Current Measure

- Depth

- Battery Strength

1. Signal Strength: Indicates your proximity to the center of the

electromagnetic eld emitted by the utility.

999: maximum value
0: minimum value

You may nd different locations

where the Signal Strength value is
high. Use this reading as a relative
indicator as to where the utility is
located. Signal Strength is strongly

inuenced by the depth of the

utility.

2. Left/Right & Over-Target: These indicators show your position

relative to the center of the electromagnetic eld.

Move to Move to You are over
the left the right the target

9

TW-82P RECEIVER

NO SOUND

STANDARD MODE continued

Audio: When you move within a 45º angle of the center of the

electromagnetic eld, the audio pitch will change; the pitch
increases as you approach the utility. Outside the 45º zone, the

pitch does not change.

When the Receiver is directly over the utility, it goes silent. The over­target indicator, •, also appears when the Receiver is directly over

the utility.

DIRECTLY OVER UTILITY

CONSTANT

PITCH BEYOND 45°

PITCH INCREASES

AS YOU APPROACH THE UTILITY

VOLUME DECREASES WITH DISTANCE FROM UTILITY

CONSTANT

PITCH BEYOND 45°

45°

When you are standing to the right of the utility, you will hear

a constant tone, and to the left, a pulsating sound.

3. Azimuth: These rotational arrows indicate the utility’s path

relative to your position. The arrows will point in the direction of

the utility’s path as the Receiver is

rotated near a burried utility.

4. Current Measure:

mA (milliamperes) of current
owing on the conductor.

Use Current Measure as an aid

for distinguishing utilities in close

proximity. The Current Measure

will generally be the highest on the

utility you are connected directly to,
regardless of the utility’s depth.

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10

TW-82P RECEIVER

STANDARD MODE continued

5.Depth:

The depth reading is only accurate if the electromagnetic

eld is perfectly round.

The electromagnetic eld must have enough energy for the

Receiver to accurately calculate the depth. The weaker the
signal strength, the less reliable the depth indicator. For this
reason, depth readings for inductively located utilities will

tend to be less accurate than conductively located ones.
The depth reading is a measure of the distance between the tip

of the Receiver blade and the center of the buried utility. When
the device is directly over a buried utility, as indicated by the
Over-Target indicator, depth will automatically be displayed in
feet and inches (meters if metric).

In general, the accuracy of any

depth measurement will be

inuenced by factors such as
proper azimuth orientation of
the device, eld strength and
the roundness of the eld. The
only 100% reliable method for

determining the depth of any
buried utility is to hand-excavate.

6. Battery Strength: When battery life declines to less than one hour

of operation, the battery indicator outline will be illuminated

with no segments. When the
batteries reach the end of their

useful life, the screen will go

blank and the battery icon will

ash before the Receiver shuts
off. Expect about 100 hours of

battery life from a set of high

quality D-cell alkaline batteries.

NOTE. Overhead Power Line

Interference: When the Receiver encounters an interfering

overhead electrical eld stronger than the eld from an energized
buried line, the Receiver will display zeros, “000”, for the Depth
and Current measurements.

In this case, the eld from the overhead power line is interfering

with the signal from the buried line you are trying to trace. You

may still be able to trace the buried line, but the accuracy of your

trace will be impaired by this interference.

11

TW-82P RECEIVER

LATERAL MODE

At some sites, utility lines branching off from a main line may be
difcult to trace using the Standard Mode. In
these circumstances, use the Lateral Mode.

At such sites, the signal from a main

line is so strong that it overwhelms
the single from a lateral line. In

this illustration, gas service

lines connecting to homes
from a main gas line may
carry far less current than
the main line. This weaker
current could be the result
of a lateral line that is

shorter than the main line,

or a lateral that is not well
grounded.

When conducting a trace of the Lateral line, select LATERAL Mode
and walk parallel to the main line (as in the illustration below). You
must use Lateral Mode in this situation because in the Regular Mode,

you may detect the signal from the main line all of the way up to the

house, even with the blade of the Receiver parallel to the main line.

The Lateral Mode is
congured to ignore the

signal coming from the
parallel main line and
detect signals coming
from the perpendicular

lateral lines. The Lateral

Mode may still detect
the main line in very

close proximity, even
though the Receiver

blade is parallel to it. So
maintain a minimum
distance of 6 to 12 feet
from the main line when
tracing lateral lines.

Walk parallel to the

main line, holding the
blade of the Receiver

perpendicular to the
lateral lines.

12

WALK PARALLEL TO MA N L NE

LATERAL LINE

Blade is
perpendicular
to lateral line

LATERAL LINE

TW-82P RECEIVER

LATERAL MODE continued

Press to enter Lateral Mode.

will appear on the LCD display.

LATERAL TRACING OPERATION

While tracing a line using the Lateral Mode, the display will appear as
illustrated below. The SIGNAL number indicates the strength of the
eld emitted by the buried line. The buried line is located at the spot
where the maximum SIGNAL number
is indicated. If you move left or right

of the spot where the maximum

SIGNAL number is found, the value

displayed will fall.
Walk across the location of
the lateral line with the blade
perpendicular to the lateral line.

Programming:

While in Lateral Mode, press-and-hold to program:

• To exit Lateral programming, press-and-hold again.

• To set the upper limit of the signal range, press .

Each press of toggles through the program choices:

50, 100, 150, 200, 250 or 300

Set this upper limit just above the maximum SIGNAL strength

number that appears during your lateral trace.

The correct setting will make it easier to hear the peak in the
signal as you pass over the lateral line.

Set the number just above the highest SIGNAL number.

Examples:

If the highest lateral
SIGNAL number is:

Changes to this upper limit of the
SIGNAL RANGE are saved to memory.
Changing this upper limit is similar
to the gain adjustment on other line

tracers which use a peak mode of

operation. Set the number just above
the highest SIGNAL number, as

described above.

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137
159
310

Set to:

150
200
300 (300 is the maximum possible)

13

TW-82P RECEIVER

PASSIVE POWER MODE

While the Standard and Lateral Modes use the 82kHz signal injected
by the Transmitter, in some cases it is desirable to locate buried

utilities by tracing electric power currents running through them.

Buried utilities may be energized by the electric power currents
running directly through them, current coupling into them as a result
of leakage from power cable faults, defective electrical loads that leak
AC power into ground connections or from cathodic protection on

metal pipelines.

The Passive Power Mode detects both 50Hz and 60Hz electric currents
as well as harmonics of these frequencies resulting from distortions
caused by electrical loads being served by the utility. Cathodic
Protection (at 100Hz or 120Hz) is also detected. This mode will usually,
but not always, detect underground AC power lines. It does not detect

voltage and will usually not detect a power line which is not delivering

current, i.e. one that is not under a load. The operator must use his
knowledge of infrastructure and each specic area being located to

interpret the character of each underground utility.

ABSENCE OF A DETECTABLE POWER SIGNAL DOES NOT
GUARANTEE THAT NO POWER IS PRESENT.

Among the important uses of the Passive Power Mode is to check
ground connections being considered for use as a transmitter
connection to do a conductive trace. Many “grounds” are in fact

improperly grounded and/or have substantial AC power
flowing through them due to defective installation or defective

loads. Ground connections should always be treated as though they
have dangerous voltage or current on them. If the Passive Power
Mode detects power current owing in a proposed ground connection,

it is usually advisable to use some other ground connection if

available. REMINDER: This mode does not detect voltage. A oating

ground with power voltage on it will probably not be detected. A

high-impedance AC voltmeter can be used to detect voltage provided

that another ground is available to measure the voltage differential.
Floating grounds with full line voltage on them can usually be detected
with a neon bulb line tester without the need for a second ground
connection; follow the instructions provided by the manufacturer.

14

TW-82P RECEIVER

PASSIVE POWER MODE continued

Operating Controls

Press to enter Passive Power Mode
The display will appear as
illustrated to the right.

Press to increase gain.

Press to decrease gain.

Press again to exit Passive Power Mode.

Locating Procedure

1. Enter Passive Power mode.

2. Set gain at maximum, 100%.

3. If necessary, reduce the gain so that the Receiver is silent when

not over a detectable power line.

4. Walk forward, swinging the Receiver from side to side.

5. When a line is located, the Receiver will emit a raspy/buzzing

sound.

Note: Audible-search only. No visual indicators.

Passive Power detection relies only on audio feedback to locate

the utility. No indicators will appear on the LCD display.
Azimuth, depth and left/right guidance will not be provided.

6. When an audible signal indicates the detection of a utility:
a. Move left and right, sweeping beyond the range of the signal

each time as you sweep the Receiver.

b. Determine the approximate center of the signal, midway

between the right-most and left-most edges of the audible
signal.

c. Lower the gain as you sweep left and right of the approximate

center. This will narrow the search.

d. Continue to lower the gain to the minimum possible while still

detecting the buried utility with an audible alert.

7. With the utility pinpointed at one spot, move both forward and

backward to verify the direction of the utility.

8. If possible, follow the signal to a known access point, or origin, to

nd a connection point visible above ground.

9. If appropriate, use inductive or conductive modes to locate the

utility and verify the location of the utility.

15

TW-82P RECEIVER

WALK WITH BLADE

PASSIVE POWER MODE continued

Grid Search: To ensure complete coverage of the area, map out a grid of

intersecting lines covering the search area. Walk the grid at intersecting

right-angles. Power lines will be detected when the blade of the Receiver

is perpendicular to the utility. You will not detect the line when crossing
over parallel to a utility.

PERPENDICULAR

TO THE UTILITY

SEARCH
IN A GRID

UTILITY WILL NOT

BE DETECTED WHEN

THE RECEIVER

BLADE PASSES PARALLEL

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Display during Programming

TW-82P RECEIVER

AUTO POWER-DOWN, RECEIVER

When 90 minutes have passed without the operator pressing

any control buttons, the Receiver will automatically power

down.

• Lower left of the display will indicate “OFF”.

• Lower right of the display will count down from 10 to 0.

• The Receiver will then turn off.

To stop Auto Power-Down, press any button once.

METRIC / IMPERIAL UNIT OF MEASURE

To change the Receiver unit of measure, follow this procedure:

1. Start with the Receiver OFF.

2. Press-and-Hold for 6 seconds.
a. The Receiver will turn on in Standard mode.
b. After 6 seconds, the new unit of measure will indicate at the

bottom of the display.

c. If you continue to hold , the alternate unit of measure

will be displayed.

d. When you see the desired unit of measure, release . The

Receiver will commence operation using the last displayed

unit of measure.

IMPERIAL

METRIC

17

SPECIFICATIONS

RECEIVER

Frequency ..................................... 82.175 kHz

Standard Mode ............................. Automatic response

Lateral Mode

Left/Right Guidance ..................... Audible and visual

Azimuth Indicator ........................ Visual

Over-Target Indicator ..................Visual and audible

Battery Status .............................. Visual

Signal Strength Indicator ............ Numeric display & audible

Signal Current Measurement .....Numeric display, automatic

Depth Measurement ....................Numeric display, automatic

Battery Type ................................. Two D-cell batteries (included)

Battery Life ..................................From 80 to 130 hours, depending

on the volume setting

Weight, with batteries ..................3.60 lbs

Passive Power ............................... 50Hz and 60Hz detection.

Cathodic Protection detection.

TRANSMITTER

Output Frequency ........................ 82.175 kHz

Output Power (nominal) ..............Normal Setting = 0.25 watt

High Setting = 1.0 watt
Conductive Tracing Normal Power: 2 to 8,000 ohms -6dB
Impedance Matching Range
Inductive Tracing Normal Power: 15 Vm
Magnetic Strength High Power: 25 Vm

Battery Type ................................. Four D-cell batteries (included)

Battery Life ..................................Typically

with high quality alkalines

Weight, with batteries ..................4 lbs

................................ Programmable

................

High Power: 2 to 3,000 ohms -6dB

.................

130 hours

2

2

ENVIRONMENTAL

Ingress Protection Rating ............IP65 (stands up to water jets)

Operating Temperature Range ....-4ºF to 140ºF (-20ºC to +60ºC)

Relative Humidity ........................0 to 95% noncondensing

Shipping Weight (packaged) ........17.5 lbs

Field Carry Weight, w/accessories

*Includes Carry Case, Batteries, Ground Rod and Conductive Tracing Cables

Fisher Research Laboratory does not warrant suitability to specific use.
Fisher Research Laboratory shall in no event be liable for any direct,
incidental, consequential or indirect damages.

18

.15.5 lbs*

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19

TW-82P ACCESSORIES

3-Inch
Coupling Clamp
–

CCLAMP-3

Useful for in-service and
electrical power line tracing
when a metal-to-metal hookup is

not possible

5-Inch
Coupling Clamp
–

CCLAMP-5

Useful for in-service and
electrical power line tracing
when a metal-to-metal hookup is
not possible

Hard Carry Case
– 1802050000

Shock absorbent protective hard
carrying case with contoured
foam insert custom made to
house the TW-82.
35” x 7” x 16”

Fisher Sonde Signal
Transmitter 82kHz
–

SONDE-82.175

Small transmitter used to trace
the path of non-metallic pipes
and locate blockage in lines.
Sonde is inserted into a pipe or
duct by means of a push rod and
located using a Fisher receiver.

• Rugged Design

• Long Battery Life

• Outstanding Distance & Depth
Locate up to 15’ deep

• Operating Frequency: 82.175 kHz

• Weight 6.4 oz

• Length 6”

• Diameter 2”

• Battery Life: 70 hrs

• Operating Temperature

-20 to +60 C (4° to 140°F)

• End Cap Thread 3/8”-16 x 3/4”

Wide-Mouth Ground Rod
Assembly
–

GROD-TW6-L

Heavy Duty clamp (1 1/4”
opening), with 6 1/2” grounding

rod.

MTW82P Manual Revision # 0 101615