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GEA24

GEA24

24-channel seismograph

GEA24 is a compact-sized 24 channel seismograph (can be serialised for a total of 48 chan.) with a 24 bit data acquisition board and USB interface for external PC (not included in the standard supply). Suitable for refraction, seismic tomography, downhole, crosshole, Vs30, MASW, shallow reflection applications, GEA-24 is a reliable, affordable solution for all professional uses. Connected to your PC laptop or tablet, GEA24 becomes a seismic tool that is simple to use, but with top-level performance. An external 12V battery (heavy and bulky) no longer needed: GEA24 consumes very little and is powered directly from the PC, guaranteeing a long day of work on-site. GEA24 can acquire using geophones with any resonance frequency (even 1Hz). To get 48 simultaneous channels, just connect two GEA24s to the same PC, perhaps using the Radiotrigger accessory and using a land streamer or a hydrophone chain. Versatility is what makes this our best selling product.
Models
Methodologies
REFRACTION
REFLECTION
SURFACE WAVES
BOREHOLE SEISMICS
HVSR / NAKAMURA

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DO YOU   NEED 48 CHANNELS?

2XGEA24

can be serialized for a total of 48 channels and connected to the same external PC via the appropriate USB cables (on the PC you need 2 USB ports).GEA24 checks the presence of two systems and identifies them with their serial number. Step by step, the acquisition software will allow you to draw the geometry of the spreading in relation to your seismic cables (12 or 24 channels) and the 1-48 geophone sequence you are using in the field.

The Multitrigger Box - connected to the first GEA24 unit - will guarantee the perfect synchronization of the trigger pulse on all 48 channels. As a complement to your 48-channel system, the PASI Radiotrigger could then become a viable alternative to long trigger extension cables.

 

GEA24 ACCESSORIES

SEISMIC CABLES
SEISMIC CABLES

PASI seismographs can be accompanied with a complete range of 12 or 24-channel seismic cables for refraction/surface reflection. Alternatively, land streamer and customised hydrophonic cables are also available, for quick acquisitions on land, at sea or in wells.

GEOPHONES
GEOPHONES

Geophones used in geophysics are sensors designed to detect ground movements or seismic waves. The sensitive element is similar to a microphone, but capable of detecting even very low frequencies (up to 1 or 2 Hz) and transforming the detected signal into an electrical impulse. In fact, an electromagnetic geophone generates a current when the arrival of the seismic wave, artificially produced in the ground by a controlled seismic source or spontaneously produced by a natural or anthropic source, determines the relative motion of a coil inside a magnet.

3DLG-2
3DLG-2

The 3D Land Geophone 3DLG-2 is the ideal accessory to add to your seismic instrumentation and perform HVSR, MASW and Vibration Analysis. One vertical and two horizontal high-performing sensors, with 2Hz resonance frequency and properly coupled, are mounted in a robust waterproof case, delivered with adjustable feet and inter-changeable rods.

GFA
GFA

Borehole 3D Geophone Mod. GFA 50/100 is built with 3 high-sensitivity geophones (nat.freq.10 Hz- 1 vertical and 2 horizontal sensors) oriented according to a triad of orthogonal Cartesian axes XYZ. Supplied with a cleat assembly to sustain its weight at the requested depth (GFA cable is graduated in meters), this borehole geophone has a pneumatic-mechanical clamping system with lateral lever and spacer block. Available in two versions: GFA-50 with 50m of cable and GFA-100 with 100m of cable.

CHE
CHE

Specially designed for small-scale crosshole surveys (ASTM 4428), this compact hammer can be used to generate both P and S waves. The hammer can be loaded down using the steel cable and clamped to the requested depth by a pneumatic clamping system manually controlled by a lever from the surface.

VERTICAL 10HZ STARTER GEOPHONE
VERTICAL 10HZ STARTER GEOPHONE

Starter geophone with connecting cable. The ideal solution for having a perfect trigger and acquisition. Standard cable length is 1m (longer lengths available upon request).

PIEZOELECTRIC STARTER
PIEZOELECTRIC STARTER

Piezoelectric starter (hammer switch), with cable. Supplied with spare piezoelectrics.

TRIGGER EXTENSION CABLE
TRIGGER EXTENSION CABLE

Shielded cable on reel, length 130m, for starter geophone / hammer switch.

RADIO TRIGGER
RADIO TRIGGER

Versatile, user friendly instrument, designed to "trigger" the acquisition of the seismograph via radio, transmitting in the free European band 869.4 - 869.65 MHz (free use license - exempt from government taxes).

SLEDGE HAMMER 6 KG
SLEDGE HAMMER 6 KG

6kg sledge hammer. Can be used either with a hammer switch (to be fixed to the handle of the hammer as in the photo) or in combination with the starter geophone.

STRIKING PLATE
STRIKING PLATE

Aluminium striking plate with carrying handle, dim. 20x20x5 cm. Also available in polyzene version (upon request).

HORIZONTAL WAVE STRIKING PLATE
HORIZONTAL WAVE STRIKING PLATE

Iron/aluminium horizontal wave striking plate.

ISOTTA
ISOTTA

When energizing with the sledge hammer is no longer sufficient data - to reach the desired exploration depth and explosives cannot be used, this seismic energizer can be the winning solution (for example when you need to acquire seismic reflection data). The Isotta seismic energizer is made up of a stainless steel cylindrical body, with a front section that may be unscrewed (cartridge chamber), suitable to contain an 8-bore blank cartridge, or industrial type, easily found in gun shops. This cartridge chamber is without barrel, thus permitting the axial ejection of the energy wave, caused by the explosion of the cartridge, generating type 'p' (longitudinal) and type 's' (transversal) waves.

MULTITRIGGER BOX
MULTITRIGGER BOX

This accessory allows the trigger synchronization between two separate acquisition units; it's compatible with Gemini-2, GEA3, GEA24.

GPS OPTION
GPS OPTION

USB GPS antenna; it can be used for geopositioning of an instrument connected to PC (es. GEA24, GEA3, RM-1, POLARES32, Gemini-2) or for synchronization of acquisitions among more instruments (es. 2 or more Gemini-2s).

TECHNICAL
SPECIFICATIONS
GEA24

5-YEAR WARRANTY

Number of channels
24 chs + trigger (AUX ch) -
2 units can be serialized for a total of 48 chs
Data Conversion
24 real bits Sigma-Delta ADC (compatible with analog geophones of any resonance
frequency)
Sampling intervals
Single acquisition (active and passive):
-from 1 to 6 chs : up to 31.25 microsec/32000 Hz
-from 7 to 12 chs : up to 62.5 microsec/16000 Hz
-from 13 to 24 chs : up to 125 microsec/8000 Hz

Continuous acquisitions (passive):
-from 1 to 3 chs : up to 500 microsec/2000 Hz
-from 4 to 6 chs : up to 1 millisec/1000 Hz
-from 7 to 12 chs : up to 2ms /500 Hz
-from 13 a 24 chs : up to 4ms /250 Hz 
Acquisition length
27500 samples @ 24 chs (+aux)
174500 samples @ 3 chs (+aux)
Unlimited samples for continuous acquisitions
Preamp. gain
LOW (0dB) - HIGH (52dB), software selectable
Stacking
Unlimited number of stackings
Input impedance
2MOhm // 22nF
Dynamic Range
144dB (system); >117db (instantaneous, measured @1ksps
Distortion
0.007% @16kHz
Bandwidth -3dB
Bandwidth +/- 0.1dB
From DC to 6.8kHz@32ksps - from DC to 0.21 kHz@1ksps
From DC to 3.5 kHz@32ksps - from DC to 0.11 kHz@1ksps
Filters
Low Pass:125-200-500-1000Hz
High Pass: 10-20-30-40-50-70-100-150-200-300-400Hz
Notch Filter
50-60Hz + harmonics
Trigger
Normally closed contact, normally open contact (e.g. with explosive),
analog signal (starter geophone, hammer switch), TTL triggering.
Trigger sensibility adjustable via software
Trace Display
Wiggle-trace / variable area
Noise-monitor
All channels + trigger; real time display
AUX channel
1x (for trigger or any other input signal)
Communication interface
1x USB 2.0 to external PC (not included)
Data format
SEG2 (other formats available on request)
Power supply
5VDC from USB, 0.25A
Operating/Storage
Temp. from -30°C to + 80°C
Humidity
80% relative humidity, non condensing
Dimension and weight
24cm x19.5cm x11cm, 2kg Shock-resitant PELI CASE IP67
Technical specifications subject to change without notice
Number of channels
24 chs + trigger (AUX ch) -
2 units can be serialized for a total of 48 chs
Data Conversion
24 real bits Sigma-Delta ADC
(compatible with analog geophones of any resonance frequency)
Sampling intervals

Single acquisition (active and passive):
-from 1 to 6 chs : up to 31.25 microsec/32000 Hz
-from 7 to 12 chs : up to 62.5 microsec/16000 Hz
-from 13 to 24 chs : up to 125 microsec/8000 Hz

Continuous acquisitions (passive):
-from 1 to 3 chs : up to 500 microsec/2000 Hz
-from 4 to 6 chs : up to 1 millisec/1000 Hz
-from 7 to 12 chs : up to 2ms /500 Hz
-from 13 a 24 chs : up to 4ms /250 Hz

Acquisition length
27500 samples @ 24 chs (+aux)
174500 samples @ 3 chs (+aux)
Unlimited samples for continuous acquisitions
Preamp. gain
LOW (0dB) - HIGH (52dB), software selectable
Stacking
Unlimited number of stackings
Input impedance
2MOhm // 22nF
Dynamic Range
144dB (system); >117db (instantaneous, measured @1ksps)
Distortion
0.007% @16kHz
Bandwidth -3dB
Bandwidth +/- 0.1dB
From DC to 6.8kHz@32ksps - from DC to 0.21 kHz@1ksps
From DC to 3.5 kHz@32ksps - from DC to 0.11 kHz@1ksps
Filters
Low Pass:125-200-500-1000Hz
High Pass: 10-20-30-40-50-70-
100-150-200-300-400Hz
Notch Filter
50-60Hz + harmonics
Trigger
Normally closed contact, normally open contact (e.g. with explosive), analog signal (starter geophone, hammer switch),
TTL triggering. Trigger sensibility adjustable via software
Trace Display
Wiggle-trace / variable area
Noise-monitor
All channels + trigger; real time display
AUX channel
1x (for trigger or any other input signal)
Communication interface
1x USB 2.0 to external PC (not included)
Data format
SEG2 (other formats available on request)
Power supply
5VDC from USB, 0.25A
Operating/Storage
Temp. from -30°C to + 80°C
Humidity
80% relative humidity, non condensing
Dimension and weight
24cm x19.5cm x11cm, 2kg Shock-resitant PELI CASE IP67
Technical specifications subject to change without notice