High density electrical apparatus is a traditional method based on the theory of a new generation of electrical equipment in the development of computer and information monitoring based on modern science and technology. In the case of overweight to solve the power supply equipment, instrument more portable, using program control, makes the primary pole will be able to complete the signal acquisition task more, greatly reduce human error, improve work efficiency, reduce the intensity of work.
<strong> High density electrical prospecting work method</strong>
On line pre selected and measured points, at the same time arrangement of dozens or even hundreds of electrodes; and then connect them to the special electrode conversion device for multi core cable; the latter can according to the operator's instruction, by the program of measuring instrument control will be combined into the electrode electrode and the electrode device specified distance, resistivity method observation of rapid completion of various electrode device and multi electrode spacing in a plurality of measuring points on the observed profile. With the corresponding data processing, mapping and interpretation software can complete a given task in geological exploration.
<strong> High density electrical prospecting characteristics</strong>
(1) the electrode arrangement is completed once, which not only reduces the electrode caused by faults and disturbances, and laid the foundation for rapid and automatic measurement of field data;
(2) scan measurement of many kinds of electrodes effectively, which can be obtained on the geoelectric section structure of geological information is abundant;
(3) field data collection automated or semi automated, not only the acquisition speed (about every measuring point to 2-5s), and to avoid the emergence of manual operation error;
(4) part of the instrument can preprocess the data and display the profile curve, offline can also automatically draw and print all kinds of maps after treatment;
(5) compared with the traditional resistivity method, low cost, high efficiency, rich information, easy interpretation. Exploration capacity significantly increased.
Electra is the latest technology for 2D and 3D geoelectric prospecting resistivity imaging, the use of the MOHO company after 30 years of research and development, the natural excitation potential measurement of patent technology in the field of neural network is introduced to the geophysical sciences.
This paper introduces some application examples of Electra alternating current high density electrical apparatus, relates to small, medium and large scale field investigation.
<strong> 1, a small scale survey: cavity detection</strong>
In 2, the scale of investigation: cavity detection
The number of electrodes in 64 line length of about 95 M
The arrangement type Wenner maximum prospecting depth of about 15 m
The current intensity of 10 mA
In 3, the scale of investigation: Civil Engineering Applications
The case is the application of a high density resistivity method in civil engineering. Here, Electra was used to investigate the building foundation, and find an abandoned use of the sewage treatment pool.
In 4, the scale of groundwater survey: Survey
The case collected from a city landfill field (note that the typical terrain profile), to determine the water seepage channel (low resistivity and high resistance), abnormal indication landfill location. Pay attention to the underground as shown in the figure below this extremely uneven, is a typical characteristic of landfill.
5, large-scale bedrock survey: Drawing
Electrical prospecting can be skilled for drawing and bedrock landslide investigation and other large-scale exploration activities. Below the case for almost isotropic rock (on) and faulted Bedrock (down). Please note that the current intensity is Electra only minimal, can achieve the exploration depth of 60 meters.
Electra is mainly composed of a central control unit, the end of the cable with a USB interface to connect to any PC or palmtop computer, the other end is connected to a cable digital signal booster, function module. The digital module has two functions: the current injection formation; electrical testing from the formation, the signal source (electrode) to complete signal amplification, digital processing. The main digital signal transmission cable transmission through lightweight, high strength of the central control unit, there is no signal crosstalk and attenuation, better signal quality.
Electra can be of different forms and different input current formation frequency, were tested using alternating current speed, higher accuracy. Because the alternating current need not like DC, you need to supply certain time to ensure the stability of the signal, and can avoid the measurement error caused by the excitation of the electrode polarization. In the active and passive source, all channels (up to 255) are at the same time synchronization for data collection, and is not affected by the acquisition time limit.
<strong> The main advantage</strong>
The faster test speed, greatly improve the quality of data
The smaller size, weight and energy consumption
- provide a new test program, the test becomes simple and intuitive.
<strong> The scope of application</strong>
The search for investigation of groundwater, voids, mineral resources, environmental pollution
The archaeological survey
The foundation and wall integrity research
The geologic division, find fault or fracture zone