RU2046378C1 - Device to determine line of route and depth of power electric cables laying and underground metal utility systems - Google Patents

Abstract

FIELD: geophysics, determination of route and depth of laying of underground metal utility systems. SUBSTANCE: device has receiving antenna input voltage amplifier, filters unit and indicators. Receiving antenna is connected to input voltage amplifier with bandwidth of 40-200 Hz and 300 Hz frequency fading of no less than 30 dB. Filters unit, depending upon examined type of underground utility system, has bandwidth of 49-51 Hz with 100 Hz frequency fading of no less than 35 dB or bandwidth of 98-102 Hz with 50 Hz frequency fading of no less than and is connected to input amplifier and to converter, to which acoustic and/or pointer indicator is connected. In the case the latter is connected to input voltage amplifier. EFFECT: increased accuracy of determination of route and depth of underground metal utility systems laying. 1 dwg

Description

 The invention relates to electrical measurements and can be used to determine the route of electric cables in normal operating mode, pipelines having cathodic protection against corrosion, and other communications in a densely populated area, namely to find a specific route, its depth in cases where the mutual influence of communications located in close proximity is great.

 Known non-contact seeker of damage to the insulation of communication [1] that allows you to search for the path and the depth of communication, consisting of the first and second converters of the magnetic field into an electrical signal, a subtraction unit, a unit for indicating the depth of the object, a current indication unit.

 The finder is structurally complex and inconvenient to operate, its low functionality.

 A device for determining the location of underground metal communications [2] adopted as a prototype. It contains a transmitting unit containing a master oscillator, power and voltage amplifiers, a phase splitter, a receiving unit containing an antenna, a sensitivity regulator, an amplification and filtering unit, useful signal and voltage amplifiers, an indicator unit, passive high and low frequency filters.

 The disadvantages of the prototype: limited functionality, namely the need to use an auxiliary excitation generator that creates an electromagnetic field around the object under study, the inability to determine the type of specific underground communication.

 The objective of the invention is the creation of a device with wide functionality that allows you to search for the cable route, which is in normal operating mode, located in close proximity to pipelines with cathodic protection, to recognize the type of underground communication, determine the depth of its occurrence.

 To this end, in a device for determining the path and depth of underground metal communications containing a receiving antenna, a voltage amplifier, filters, indicators, according to the invention, the receiving antenna is connected to an input voltage amplifier, the output of which is connected through the first switch to the inputs of the first and second bandpass filters connected parallel. The outputs of the filters through a second switch are connected to a transducer to which an acoustic indicator is connected in series. The output of the input voltage amplifier through the first switch is connected to an acoustic indicator. The arrow indicator through the third switch is connected to the output of the input voltage amplifier or through the second switch to the output of the first or second band-pass filters.

 The device includes devices made according to known schemes. However, it is the proposed set of devices, their relationship that solves the problem. Based on the foregoing, we can conclude that the solution to the problem of determining the route of electric cables under load, pipelines with cathodic protection, located in close proximity to each other, identifying the type of communication, its depth corresponds to the inventive step.

 The drawing shows a structural diagram of a device for determining the route and the depth of underground metal communications.

 The device contains a magnetic receiving antenna 1, which is an inductor with a ferromagnetic core. Antenna 1 is connected to an input voltage amplifier 2, which provides signal amplification in the band of 40-200 Hz and has attenuation at a frequency of 300 Hz of at least 30 dB, which is necessary to protect the device from interference caused by electric trams by a tram and a trolley bus. The output of the input amplifier 2 is connected through the first switch 3 to the inputs of the first and second bandpass filters 4 and 5, each of which consists of two links. Each link of the filter 4 or 5 consists of an amplifier assembled according to a cascade circuit, in the feedback circuit of which a double T-shaped bridge is included. Filters 4, 5 are band-pass filters with a passband of 6 Hz, unevenness of 2 dB and attenuation of 50 Hz with respect to 100 Hz and 100 Hz with respect to 50 Hz of not less than 35 dB. From filters 4, 5, the signal enters the transducer 6 through the second switch 7. The transducer 6 converts the frequencies of 50 and 100 Hz into a spectrum of frequencies that are well perceived by the ear. The conversion of the signal (50 or 100 Hz) by the converter 6 consists in distorting its shape using a diode (a sinusoid turns into a sequence of pulses). The converted signal is amplified by the amplifier and fed to the headphones. The amplifier and headphones are part of the acoustic indicator 8. In the "wide band" mode, the signal from the amplifier 2 through the switch 3 is sent to the acoustic indicator 8. The arrow indicator 9 through the third switch 10 is connected to the output of the input amplifier 2 or through the second switch 7 to the output filters 4 or 5. The indicator 9 at the output of the input amplifier 2 controls the level of the signal received by the antenna 1, which should be within the linear portion of the amplifier 2, and the output level of the filters 4 or 5 eyes frequency 50 or 100 Hz.

 The device operates as follows.

 The determination of the route of metallic underground utilities (electric cables, gas pipelines, heating mains, telephone cables) is based on the determination of the extreme magnitude of the magnetic field vector that occurs when alternating current flows through the utilities. It does not matter if it is a working current or a current induced from currents wandering in the ground.

 For a rough estimate of the route work with the horizontal position of the antenna 1, while the antenna should be parallel to the surface of the earth and perpendicular to the communication path. Only after "entering the path" the exact location of the path is determined with a vertical arrangement of antenna 1. The center of the path in this case corresponds to the minimum level of the received signal. If it is not known about the availability of communications in the studied area, the search must be started by switching the first switch 3 to the range of 40-200 Hz. The signal from the input amplifier 2 through the switch 3 is fed to the acoustic indicator 8.

 Upon detection of the passage of communication, specify its type by switching the first switch 3 to the range of 50 and 100 Hz. If the signal with a frequency of 50 Hz prevails two or more times, the communication electric cable is under load, and when the signal with a frequency of 100 Hz prevails, the communication pipeline is under cathodic corrosion protection.

 When antenna 1 enters an alternating magnetic field created by a current of frequency 50 (electric cable under load) or 100 Hz (pipeline with cathodic protection against corrosion), an EMF appears in it, which is amplified by input amplifier 2. From the output of amplifier 2, depending on the mode During operation, the signal is fed to a filter 4 or 5. A working frequency signal (50 or 100 Hz) is passed through a filter 4 or 5 with a passband of 6 Hz, and the interfering frequency is attenuated by at least 35 dB. The working frequency signal is converted by the transducer 6 into an audible spectrum of sound signals and fed to the acoustic indicator 8. The dial indicator 9 controls the signal level at the output of input amplifier 2 and at the output of filter 4 or 5. Level control at the output of input amplifier 2 is necessary so that the level the signal to the overloaded amplifier 2. Monitoring at the output of the filter 4 or 5 allows the operator to duplicate the acoustic indicator 8 and is necessary when determining the depth of communication.

For determining the depth of occurrence of communication are communication passage axis above manner and placing the antenna 1 with respect to the ground at an angle of ⁴⁵ °, away from communication axis passing perpendicularly thereto as long as the signal is minimal. The distance from the location on the surface of the earth of the communication axis to the place of the minimum signal is equal to the depth of the communication.

Claims (1)

 DEVICE FOR DETERMINING THE TRACK AND DEPTH OF THE POWER SUPPLY OF POWER ELECTRIC CABLES AND UNDERGROUND METAL COMMUNICATIONS, comprising a receiving antenna, an input voltage amplifier, a filter unit, indicators, characterized in that the receiving antenna is connected to a voltage input amplifier with a voltage of 40 at a frequency of 200, 300 Hz not less than 35 dB and connected to the filter block, which, depending on the type of communication being studied, has a passband of 49 51 Hz with attenuation at a frequency of 100 Hz of at least 30 dB or blowing 98,102 Hz with attenuation at a frequency of 50 Hz is not less than 35 dB, coupled with the converter to which is connected an acoustic and / or dial indicator, the latter being connected to the input of voltage amplifier.

Images