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Conductive & Non-conductive pipe locating concepts. Please ask your questions anytime…. Basic Concept of Pipe & Cable Tracing. Receiver. Strong Signal. Decaying Signal.
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Conductive & Non-conductive pipe locating concepts Please ask your questions anytime…
Basic Concept of Pipe & Cable Tracing Receiver Strong Signal Decaying Signal • In conductor tracing, the trace conductor is connected to the output of the Transmitter. The CABLEand EARTH (Ground) must form an electrical circuit where signal current can flow through. • As the current flows through the cable, its entire length radiates a signal allowing one to trace the cable path using a Receiver. • Also, as the signal travels further out, its strength gradually deteriorates until it is fully dissipated to EARTH (Ground). Red Clip Far-End Ground Current Flow Near-End Ground Removed Transmitter Black Clip Ground Rod Soil Current Flow
TERMS COMMONLY USED IN PIPE & CABLE TRACING • TRACE CONDUCTOR - any metallic component of a cable which is used to trace the pipe or cable path. (Ex: Cable Shield, a conductor of a power cable, or a telephone wire or pair inside a telephone cable, water pipe, etc.) • TRACE FREQUENCY - is the selected transmit frequency (Low, Medium, High or Ultra High) to trace the conductor path. • NEAR-END GROUND - is the grounding point of the trace conductor which is located closer to the Transmitter. • FAR-END GROUND- is the remote grounding point of the trace conductor which is located further away from the Transmitter. • TARGET UTILITY - the conductor being traced.
BASIC SENSOR TYPES USED IN PIPE AND CABLE LOCATORS • PEAK SENSOR - provides maximum signal when placed right above the trace conductor. Signal decreases when moving towards either side. • NULL SENSOR- provides minimum (null) signal when placed right above the trace conductor. Signal increases when moving towards either side.
RECEIVER OPERATION(Basic Theory - con’t...) The signal’s amplitude from the PEAK sensor is used to drive the numeric digits and to frequency modulate the audio tone. Location #1: Numeric indicator - reads higher compared to location #2 or #3. Audio Tone - highest pitch (frequency) beeping approximately 3-4 times per second. Locations #2 and 3: Numeric indicator - reads lower compared to location #1. Audio Tone - lower pitch (frequency) than position #1. POSITIVE ZERO NEGATIVE RECEIVER UPPER ANTENNA 2 1 3 LOWER ANTENNA SOIL TARGET CONDUCTOR
MORE TERMS COMMONLY USED IN PIPE & CABLE TRACING ISOLATED UTILITY FIELDS: When the target utility EM field is not affected by intersecting joints or by the presence of other utilities and is pretty much cylindrical around the target utility and symmetric. DISTORTED OR CONGESTED UTILITY FIELD: When EM fields other than the primary EM, induced onto the target utility by the transmitter, are in the vicinity of the target utility, they combine with the primary EM resulting in an asymmetrical, non-cylindrical EM field. These EM fields may naturally exist in the area (power cables, radio stations,etc.) or maybe the result of the transmitter signal inducing currents onto adjacent, non-targeted utilities.
CONDUCTOR TRACING IN CONGESTED ENVIRONMENTSExample: Sharing signal on a common bond o via return path A congested environment such as the one shown here, where there is another conductor running parallel to the main conductor being traced, presents some challenges to the locating task. The lower peak sensor will still peak at each conductor, as shown in locations 1 and 3, but at location 3 the numeric indicator (the strength of the received signal) should be less. The audio frequency will also be correspondingly lower. OTHER CONDUCTOR TARGET CONDUCTOR GHOST CONDUCTOR
MORE TERMS COMMONLY USED IN PIPE & CABLE TRACING TARGET DEPTH:The distance from the soil surface to the top of the target utility. Knowing the distance between the lower peak antenna and the upper peak antenna, and assuming we have an “Isolated Utility Field” (cylindrical), it is possible to calculate the depth based on the measured signal strength difference between the two antennas FACTORS THAT AFFECT DEPTH MEASUREMENT ACCURACY: Ground composition and density Ground moisture Distorted or congested utility fields Conductivity, size and aging of target utility Distance from transmitter source (weak vs. strong signal)
TRACING RANGE(Ideal conditions - Direct Connect With Far-End of Cable Grounded) • 512 Hz 20,000 ft. (4 miles) • 8 kHz 10,000 ft. (2 miles) • 83 kHz 3000 ft. (2/3 mile) • 375 kHz 500 ft. (.1 mile) FREQUENCIES THEORETICAL RANGE
TRANSMITTER HOOKUPS • DIRECT CONNECT METHOD • INDUCTIVE CLAMP (COUPLER) METHOD • INDUCTION METHOD
DIRECT CONNECT METHOD(Accessories Used) RED CLIP BLACK CLIP GROUND ROD
DIRECT CONNECT HOOKUP RED CLIP T1 T2 CONDUCTOR CURRENT FLOW FAR-END GROUND NEAR-END GROUND REMOVED TRANSMITTER GROUND ROD BLACK CLIP SOIL SOIL 1. Place the GROUND ROD into soil and connect the BLACK clip to it. 2. Connect the RED clip to the conductor. 3. Turn the unit ON. Refer to manual to use the current measurement and/or the output power indicator to estimate the condition of the circuit and improve your connection. This will help you decide the best frequency to use. Note: Separate common bonds if safe, accessible and practical CURRENT FLOW
DIRECT CONNECT HOOKUP (Cont..) GROUND STAKE POSITIONING: • Having a good circuit is crucial. • Proper placement of the ground stake is essential. • Good contact with soil (wet the ground if necessary) • Oriented at 90 degrees from the direction of the target utility. • Farthest possible from commonly bonded unwanted utilities.
DIRECT CONNECT HOOKUP( DO’S & DON’TS ) CONDUCTOR OPEN-END RED CLIP DISTRIBUTED CABLE CAPACITANCE C C C C C C C TRANSMITTER GROUND ROD BLACK CLIP SOIL 1. If far-end of conductor is open or not accessible for grounding - use the Higher trace frequencies, only.Note:This procedure is only applicable if length of cable is long enough (few hundred feet/meters) to permit the high frequency current to flow through the distributed capacitance of the cable. CURRENT FLOW
DIRECT CONNECT HOOKUP( DO’S & DON’TS ) SHORT CONDUCTOR SHORT CONDUCTOR FAR-END GROUND RED CLIP RED CLIP FAR-END WIRE CONNECTION A B TRANSMITTER TRANSMITTER 50 FEET(15 m) CURRENT FLOW GROUND ROD BLACK CLIP BLACK CLIP To trace very short conductors of cable, less than 100 feet (30 m): • The far-end of the trace conductor must always be grounded to EARTH/SOIL(illustration A). • If EARTH/SOIL is not accessible, a WIRE can be used as the current return path, but it must be placed 50 feet (15m) or more away from trace conductor (illustration B). SOIL CURRENT FLOW CURRENT RETURN WIRE
INDUCTIVE CLAMP (COUPLER) METHOD(Accessories Used) COUPLER Coupler available in 4” Diameter
COUPLER HOOKUP T1 T2 CONDUCTOR SECONDARY CURRENT FLOW FAR-END GROUND NEAR-END GROUND COUPLER TRANSMITTER SOIL PRIMARY CURRENT FLOW NOTE: • Do not remove NEAR-END and/or FAR-END GROUNDS. Doing so will break or open the trace circuit and “no” current can flow. • Only the Highest frequencies (8kHz or higher,preferably 27kHz or higher) will work with the Coupler. The AUDIO or Low frequencies (512Hz) will “not”. SECONDARY CURRENT FLOW
INDUCTION METHOD & HOOKUP TRANSMITTER INTERNAL TRANSMIT COIL FAR-END GROUND CABLE SHIELD PRIMARY CURRENT FLOW NEAR-END GROUND SOIL SECONDARY CURRENT FLOW Note: • To achieve best results, Transmitter must be placed over and as close as possible to the conductor and should beperpendicular to the cable path, as shown on the transmitter instructions attached to the case. • NEAR-END and FAR-END of the trace cable/conductor must be GROUNDED toSOILto maintain continuity of the trace circuit. • Use only the two highest frequencies, only (20kHz or higher frequency). • Induction Method is not recommended in congested areas because the signal can be easily induced to any other cable or pipe which is close and in parallel to the target cable. • Operate the Receiver no less than 25 feet (8 meters) from Transmitter to avoid direct reception of signal.
Non-conductive locating • PVC pipes – water & wastewater • HDPE – oil & gas lines • Clay pipes - wastewater • Cast Iron – water & wastewater • Drain tile – buildings & field • Concrete pipes • Tanks, manholes, foundations, large roots
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QUESTIONS ??? Made in USA – DePere, WI 3 years warranty Patented UHF inverted cone signal FCC, IC, CE/EU approved Thanks for your interest …. Don Hager Regional Mgr. 580-370-5319 don.hager@ssilocators.com