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MTU SERIESSatellite Synchronized Data Acquisition Units
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Download printable
specification sheet
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General Information
 The MTU is a lightweight 24-bit data acquisition unit with low power consumption, designed to operate in rugged environments. Its main applications are resistivity depth sounding and/or profiling for oil & gas, geothermal, groundwater, metals and diamond exploration; deep geophysical structure monitoring for earthquake prediction and other geological research; reservoir monitoring and management.
In general, a group of MTUs is deployed simultaneously; all units are synchronized to ±1 microsecond by time signals broadcast by satellites of the GPS (Global Positioning System); all units start/stop data acquisition at a preprogrammed date and time. The MTU data acquisition units measure up to 2 components of electric field (MTU-2E/A); up to 3 components of magnetic field (MTU-3H), or both (MTU-5/A). The data acquisition units can be combined in any proportion, in any configuration and at any spacing from tens of metres (fine detail) to tens of kilometres (wide reconnaissance), either along profiles (2-D) or grids (3-D), or repeated measurements (4-D).
In a typical survey, costs can be reduced by placing 5-component units at intervals separated by several 2-component units. (This is possible because good results can usually be achieved without measuring the magnetic signal at every site.) The two-component units do not require the capital or operational costs of purchasing and installing/retrieving magnetic sensors.
Although cable links (copper or fiber optic) are optional, in general the MTU is operated in stand-alone mode for data acquisition (no cable links) to avoid the problems associated with cables. The MTU-CL is specialized version which does not perform data acquisition, but instead uses the GPS time to provide precision timing signals to other instruments.
The MTU-LR is a version specialized for long-period MT measurements (to periods of approx. 30,000 seconds) for ultra-deep investigations. The MTU-LR uses specialized magnetic sensors. The MTU-5D is a specialized version for automated observatory operation. The MTU-CR is a version for controlled source measurements including complex resistivity (CR) [also known as Spectral Induced Polarization (SIP)] and requires a separate transmitter. The MTU-2EA and MTU-5A are designed for AMT work; the MTU-LT is for LOTEM applications.
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Applications
| MT | Standard MT frequency range from 384Hz to 1,800 Sec using MTU-5 or MTU-5A (5 component measurement), MTU-2E or MTU-2EA (2 telluric component measurement). All distributed MTU units including remote site are GPS synchronized. |
| AMT | Frequency range of 10,000Hz to 1 Hz using MTU-5A and/or MTU-2EA, AMTC-30 magnetic sensors |
| LOTEM | LOTEM time-series data acquisition with GPS synchronized high power transmitter using MTU-LT |
| Long Period MT | Period as long as approx. 20,000 Sec. with MTC-50 magnetic snesors using 5-7 days soundings |
| SIP | Spectral IP (or Complex Resistivity) measurement with GPS synchronized transmitter using MTU-CR |
| CSAMT | CSAMT measurement with GPS synchronized transmitter |
| CLOCK | Provides GPS-synchronized driving signal to control transmitter and/or other type of receiver for precisely synchronized operation using MTU-CL [Note: MTU-CL does not use an ADC] |
Specifications
| Functional |
| Number of Channels : | 1 to 5
Input range: 25mV,..., 1200mV (Standard unit)
± 10V (MTU-CR, MTU-2EA, MTU-5A)
with practical dynamic range of 130dB |
| Input Impedance : | > 1 Megohm |
| Frequency range : | 1/1800 Hz to 384 Hz (MT)
1 Hz to 10 kHz (AMT, CSAMT options)
1/16 Hz to 256 Hz (CR, SIP)
0.25ms to 16 sec windows (LowTEM options)
~20,000 sec to 1800 sec (long-period MT) |
| Powerline Filtering : | digital notch at all odd/even harmonics; better than 40dB |
| Other Filtering : | low pass, high pass, bandpass, resampling, etc. |
| Timing accuracy : | better than ±1 500 nanoseconds, locked to UTC
(very high stability oven controlled oscillator synchronized to GPS) |
| Calibration : | automatic self calibration for box and external sensors |
| Data Storage Capacity : | standard 128 Mb SOLID STATE
512 Mb for A model
(larger capacity on request) |
| ADC (MTU models) : | 24 bits, 4096 samples/sec max
In MTU-A models: 96,000 samples/sec max |
| Data Transfer / Set Up : | directly to PC via fast parallel port on site or in base camp
or removable memory card to PC
or via ordinary telephone line (MTU-5D) |
| Mechanical |
| Dimensions : | 230mm x 225mm x 110mm. |
| Weight : | Approx. 4 kg |
| Case : | Diecast aluminum, environmentally sealed. |
| Input Power : | Any suitable 12V battery
Solar Power Option |
| Controls : | On/Off switch |
| Indicators : | high visibility LED to signal operating status
(GPS lock, acquisition status, etc.) |
| Connectors : | external battery;
GPS antenna;
magnetic sensor input;
parallel I/O port;
ground;
electric field (binding posts) |
| Power Consumption : | approx. 10 watts |
| Environmental |
| Temperature : | operating range -20oC to +50oC |
| Shock and Vibration : | suitable for transport in bush vehicles |
| U.S. Patent No. 6,191,587 |
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