The TXM-22 is a highly efficient multi-purpose geophysical power source. It is designed for use in connection with the TXB-07 controller unit. The TXM-22 and TXB-07 form a powerful and flexible transmitter for geophysical applications such as Controlled Source Audio Magnetotellurics (CSAMT), Controlled Source Electro magnetics (CSEM) or Long Offset Transient Electromagnetics (LOTEM).
It can be operated in a wide frequency range between 0.001 Hz and 8,192 Hz. The output current is adjustable up to a maximum of +/-40A. The nominal output voltage is +/-560V.
The TXM-22 is powered by a 50/60Hz, 3-phase, 400V generator. In order to unleash the full capabilities of the system, a generator of min. 40 kVA should be used.
1/1024sec to 8,192Hz
3 phase 50/60 Hz, 400V, socket IEC60309 32A red
+/- 560V (1120V peak to peak)
|Max. output current|
+/-40A (80A peak to peak)
Grounded dipole or loop
|Transmitter signal wave forms|
Square wave, sine wave, triangle, sawtooth, PRBS, user defined with up to 2048 set points
By TXB-07 transmitter controller via cable with 19-pole Mil connector
Aluminum case 19”
480mm x 514mm x 354mm
|Ambient temperature range|
0°C to +40°C non condensing
|Interconnection to TXM-22|
Cable with 19 pin connector galvanically decoupled
By external laptop or touchscreen computer via W-LAN or LAN
|Ratio for current measurement|
24 Bit with up to 65,536 samples per second
Compact flash or USB stick
|Ambient temperature range|
-30°C to +60°C
406mm x 330mm x 174mm
By TXM-22 or external 12V battery
Ruggedized waterproof plastic case
roll out cables
wave form edit
GSP synced cluster
There are some items which are mostly not supplied directly from us. They are quite heavy or they can be bough locally at lower price:
Most Important for alomost all users:
Due to safety regulations you need a insulation transformer. An insulation transformer is a transformer wich "transforms" the volatge 1:1 (normal transformer would do 1:10 for example to transform 2kV down to 220V). The dimension of the insulation transformer must be 20% bigger than the generator;if your generator has 32kVA you take a transormer for 38-40 kVA..
You inject currents into the ground with the transmitter; and you generate electricity with the generator.
The generator must be grounded; however - you try to ground the into the same earth where you inject the currents.
The ELCB (earth leakeage circuit braker) will break and stop the generator.
To prevent this you must have a insulation transformer to seperate source from currents.
Price is around 3200 EUR plus transportation. Examples here amadori srl (this first three phase transformer which appears in the list for example).
DRY Type POWER Series
According to IEC 726 CEI 14-8 EN 60076-1
(first picture shows 10mm2 double insulated cable, for highest security)
6mm2 default cable on cable drum / winch
As source you can use ANY 380 - 440 V / 50-60 Hz power generator with 40kVA and more.
Deutz diesel generators start at 19,200 EUR (trailer mounted) and shipment starts at 3200 EUR.
It may be recommended to buy similar in your country.
A smaller transmitter (20 kVA) can be used for small dipoles in more resisitive areas.
If the current gets too high, the TXM-22 can limit the output current to prevent the generator to be overpowered.
A smaller generator with 30 kVA:
Eletrodes can be rods; some institutes use rods down to 7m into the ground (as the geologists use for probes).
In humid (wet) areas some use plates or even aluminum foil (for example inside rice fields).
picture below shows high security electrode, upper part shielded
more simple electrodes
electrodes connectred to ground
In most areas deep burriage is preferred, because at greater depth the humidity is constantly higher and the transmitted currents are well coupled to the ground.