ARMT-5 — 5-channel 16/24-bit broadband EM system

ARMT-5 complex is designed for implementation of a variety of electric survey methods: AMT, CSAMT, CSEM, RMT, CSRMT. Its wide frequency range (0.1 Hz–1 MHz) makes it possible to apply this tool to explore depths fr om first meters up to several kilometers for wide range of targets.

ARMT-5 recorder allows one to visualize data in real time in both time and frequency domains. To quality control, a robust estimator of tensor and scalar transfer functions (impedance and tipper) is built-in. The receiver has several useful features for a controlled source EM exploration. The receiver is equipped with a built-in sine signal generator for automatic calibration (including calibration of magnetic sensors) and programmable external amplifiers for magnetic and electrical sensors (gain: 1–256). Sophisticated functionality, application of the most up-to-date element base, good-quality connectors and case, large color screen, fast interfaces for downloading data from SSD drive, and other technical solutions make ARMT-5 modern, convenient and versatile broadband electromagnetic tool.

• ARMT-HF with operating frequency range 1–1 000 kHz
• ARMT-MF with operating frequency range 20–20 000 Hz
• ARMT-LF with operating frequency range 0.1–20 000 Hz

Magnetic MF and HF sensors are placed in a single plastic container with a bubble level and display for digital compass in its upper part. Antennas ARMT-LF can be additionally equipped with portable precision tripods, allowing, fast and accurate installation of sensors on any surface.

The estimated penetration depth of the ARMT-5 complex is presented in the table below. It depends on the frequency of the signal and the average electrical resistivity of investigated section:

An important feature of the complex is a high execution speed of observations when performing shallow studies due to implementation of automated and remote control of a controlled source (generator) over a radio channel. For example, in order to perform measurements with frequencies from 100 Hz and higher taking into account the time for spreading and assembly of measuring equipment at a point, it takes only about two minutes. Such speed of data acquisition is unattainable for other complexes and methods. For example, to perform VES at depths of about 300–500 m, it takes about half an hour, what is 10–20 times longer than working with ARMT-5. It is also important to understand that the inversion of ARMT-5 data can be performed both in 1D and 2D variants, and interpretation of VES data is carried out only for 1D model, what leads to an increase in the error of constructing the geoelectric section in a complex medium.

The high-impedance input of the preamplifier of electric channels realized in ARMT-5 allows to work with short (20 m) ungrounded lines at frequencies from 100 Hz and higher. This is especially useful when working in winter conditions or in arid areas, wh ere it is difficult to achieve acceptable grounding with conventional electrodes. When operating at frequencies from 0.1 Hz it becomes necessary to use longer (50–100 m) electric lines that are grounded by non-polarized or brass electrodes.

• Study of geological structure
• Structural geographic mapping
• Determination of rock depth
• Mapping of karst structures, fracturing zones and zones of high humidity
• Search for underground water
• Monitoring of dangerous processes
• Search, exploration and monitoring of hydro-therms
• Permafrost studies
• Environmental studies
• Search and exploration of deposits of solid minerals
• Search for oil and gas

• Recorder ARMT-5
• Battery charger
• External GNSS antenna
• Power cable
• Сomm cable
• USB with software
• Documentation.

• Low-Frequency magnetic coil sensor
• Electric lines
• Non-polarizing electrodes
• Portable Precision Tripods
• Controlled source with radio modem.