GMT 1200 get started guide
Geomagnetic tracker 1200 is a latest technology geomagnetic sensing equipment suitable for groundwater investigation based on geomagnetic sensing technique. The technology is adapted based on hysteresis of earth’s magnetic field.
Hysteresis measurement have become an important part of characterizing magnetic behavior of rocks in paleomagnetic studies.
The geomagnetic sensing system helps in calculating the BH values of the rock geology and its direction which provides evidence in scientific survey for groundwater.Groundwater can influence the geomagnetic field measured underground in at least two key ways. The water levels in rock will determine its electrical conductivity, and thus change the magnitude of the telluric currents induced in the rock by changing magnetic fields generated in the ionosphere. This can be studied by using multiple magnetometers at different underground locations. Secondly the flow of water through rock will generate a small magnetic signal, of unknown magnitude, through the electrokinetic effect. SQUID magnetometry has the potential to allow passive studies of groundwater changes in complex systems such as karst. We have monitored geomagnetic signals using two SQUID magnetometers at the LSBB underground laboratory and set an initial limit on the magnitude of the electrokinetic signal. We now plan to carry out a long-term measurement using three SQUID systems as well as fluxgate sensors to track changes in the gradient of the magnetic field across the underground complex.
George Backus, Robert Parker, and Catherine Constable, Cambridge University Press, New York. 1996, ISBN 0-52141006-1
The study of the magnetic field of the Earth, or geomagnetism, is one of the oldest lines of scientific enquiry Indeed, it has often been said that William Gilbert's De Magnete, published in 1600 and predating Isaac Newton's Principia by 87 years, can claim to be the first true scientific textbook; his study was essentially the first of academic rather than practical interest. What then, we may ask, has been accomplished in the nearly 400 intervening years up to the publication of Foundations of Geomagnetism? In short, a wealth of observational evidence, considerable physical understanding, and a great deal of mathematical apparatus have accrued, placing the subject on a much surer footing. The latter two categories are described in considerable detail, and with attendant rigor, in this book. The sphericity of the Earth means that a frequent theme in the book is the solution of the partial differential equations of electrodynamics in a spherical geometry It should be said that Foundations of Geomagnetism is not for the mathematically fainthearted. But for the reader willing to stretch her or his mathematical knowledge, much can be gained. It should also be said that there is material of considerable interest to those working outside of geomagnetism—in the fields of geodesy, seismology, and perhaps astronomy the exposition of some of the fundamental concepts, such as the development of spherical harmonics, is clear and also at a level of detail higher than that found in most treatises. The book begins with a brief introduction to the main magnetic field. The book's emphasis does not claim to be phenomenological study.
GMT -1200 TECHNICAL SPECIFICATIONS
|Powersource||External 5V D.C rechargeable|
|Application||GIS, coordinate mapping, Geomagnetic field sensing, Real time values Depth Range: 500 M (sedimentary strata or other rock unit in stratigraphic and petrologic studies)|
|Axis||Tri Axis X, Y, Z|
|Manufactured||Made in India|
|Demonstration||Theory, practical and field investigation (For abroad customers we provide a complete online assistance in processing our equipment)|
GMT-1200 INSTRUMENT APPLICATION
- • Subsoil groundwater prospecting at shallow, medium and great depth.
- • Geological stratigraphy
- • Studies of salt water contamination in fresh water layers
- • Landslide monitoring
Product & Parts
- 1) Display unit
- 2) Hand held sensing system
- 3) Data transfer cable
- 4) Power bank
- 5) GPS Antenna
GMT 1200 Display unit is the main system which contains the logic unit to calculate geomagnetic frequencies received from the hand-held sensing system. The system has brightness and contrast adjustment keys, power switch to turn on the equipment, fuse to stabilize and control the power, LED indicators to indicate high zone and moderate zone, synchronize key to initialize GPS operations and the Reset key to restart the system.
The hand-held sensing system is the frequency receiving system which directly receives the frequencies generated from the ground and geomagnetic factors from fault zones and fractures. The hand-held system has a connector and a switch, where connector is used to attach the data transfer cable to the main unit and the switch turn on and turn off the operations.
The data transfer cable is of 4 cores where in the connectors are of self-slotted to attach accurately without mis positioning. One end of the cable is connected to the hand-held sensing system and the other end to the main unit.
The GPS antenna is mounted directly to the main unit, where the antenna communicates with the satellite signal to receive the coordinates of the target.
The display unit and the hand-held sensing system should be connected at the port in and port out using the data transfer cable.
Connect the power bank to the power port and turn on the on/off switch in the hand-held sensing system and in the main Display unit.
The machine starts loading followed by initializing and checking the coordinates for the survey.
Once set we get the three frequency readings in BH1, BH2, BH3
Once we start the survey from the initial point we rotate in either clock wise or in anti-clock wise until we get a maximum increase in frequency readings ranging in-between 1400 – 1500 Nano tesla depending on the area.
The highest reading frequency will be found in BH1 ad the same axis should be followed until we get a maximum increase in the reading for example from 1500 to 1550.
When there is a difference of 50 micro tesla in the axis it estimates the difference as a fracture zone.
When we have reached the fracture zone the LED indication is given in the instrument.
The technique is carried out for 5 sample points in different axis until we get the highest readings from the ground. The frequencies are generated due to the hysteresis caused from the geomagnetic factor.
The target is decided based upon the highest reading in the BH1 curve which is produced due to the magnetizing force in opposite direction and flux density in opposite direction. Thus, we need to check for the secondary axis to conform the target.
Secondary Axis positioning
The secondary axis is decided by rotating from the target when frequency readings in BH1 decreases and BH3 increases. We should now follow the BH3 axis by sensing the frequency reading where we get 30 to 50 Nano tesla differences from the starting point.
The measurement should be taken from the target to the secondary axis.
Calculation of depth
The secondary axis measurement should be calculated as per the formula given below to get the complete measurement for fractures and total borehole depth to be drilled.
For more information on the product
Complete field demonstration provided