.. _adu-08e-2C:
.. |br| raw:: html
ADU-08e 2 Channel
===================
Introduction
------------
Performance Characteristics
^^^^^^^^^^^^^^^^^^^^^^^^^^^
The ADU-08e-2C (Analog Digital Unit) is part of the metronix
multi-channel Geophysical Measurement System GMS-08. It is the result of
more than 40 years of metronix´ experience in the design and manufacture
of electromagnetic geophysical instruments.
The ADU-08e-2C is equipped with two measurement channels. The system for
wide band MT and AMT consists of 2 Broadband ADB boards allowing the
recording of 2 electric fields and in a frequency range from DC up to
250 kHz.
Each unit can be operated as a stand-alone system, in a network using
standard Local Area Network (LAN), or as part of an array, in which each
unit is synchronized by its built-in GNSS controlled precision clock. An
access via a WiFi access point is available, too.
The ADU-08e-2C electronics is housed in a small (25cm x18cm x15cm)
waterproof box only 3.5 kg in weight. In spite of the small size, it
contains the complete circuitry for analog signal conditioning, 32/24
Bit A/D conversion and data storage. A very precise satellite controlled
time base allows to synchronize multiple units.
Data is stored on a SD flash card with a capacity of up to 128GByte
(32GByte by default) which can be easily accessed by the operator. It
also can be stored on an external USB device which is connected to the
ADU.
With help of the metronix “ADUCLIENT” Control App it is possible to
operate the system via a mobile phone or a tablet PC with
Android operating system.
Either the single ADU-08e-2C or a complete network of several ADUs can
be controlled via a standard PC using the built-in web interface.
.. image:: /media/adu-08e-2C/adu-08e-2C.jpg
:width: 80%
:align: center
Features
^^^^^^^^
* High data quality due to 32/24 Bit /Digital conversion technology.
For sampling rates up to 4096 Hz an ultra-high resolution 32 bit ADU
converter is used.
* Very low system self-noise for best results in the MT “dead band”.
* Wide frequency range from DC to 250 kHz. Sampling rates up to 524.288
kHz
* System can be operated as a stand-alone or as a multi-channel network
system when connecting multiple ADU-08e-2C in a Local Area Network
(LAN).
* ADU-08e-2C is controlled by a smart phone App or by any Web-browser
without need of additional software.
* Multiple stand-alone systems are synchronized with GNSS satellite
clock accuracy.
* Compatible with all metronix sensors (see note on previous page).
* Automatic unattended recording mode.
* Plug and Play recording mode if a USB pen-drive with pre-programmed
* time schedule is inserted.
* Automated system self-check of ADU-08e-2C and sensors during set up.
* Automatic input offset compensation eliminates self-potential of
electrodes.
* Only one 12V battery is required for each ADU-08e-2C incl. sensors.
* Compact, light-weight, ruggedized and water-protected instrument
design.
* Low power consumption.
* Wide operating temperature range from -30°C to +60°C ambient
temperature.
Technical Data
^^^^^^^^^^^^^^
.. csv-table::
:delim: |
Frequency range|DC to 250 kHz (524.288 kHz in preparation)
Number of channels|2
Native sample rates of A/DS converter |8Hz to 524.288kHz (lower sampling rates by on-line digital filtering)
A/D conversion |LF: 32 Bit (data rate max. 4,096 samples/sec)
|HF: 24 Bit (data rate max 524,288 samples/sec)
|One A/D conversion unit for each channel
Input noise|LF-ADB: :math:`\\17nV/\sqrt{Hz}~@~0.1 < f < 2kHz` and gain 16
|Ultra low noise mode LF: :math:`\\6nV/\sqrt{Hz}` @gain 64
|HF-ADB: :math:`\\13nV/\sqrt{Hz}~@~f > 1kHz` and gain 16
Input resistance |:math:`\\> 10M\mathrm{\Omega}`
Nominal input voltage range (@ gain 1)|switchable between +/- 1.25V and +/-10V (is done automatically by selection of sensor type)
System computer|32 bit low-power embedded controller with Linux operating system (4 CPU cores)
Storage media|32GByte SD card (up to 128 GByte possible), USB-pen-drive or other external USB mass storage device
Test facilities|Automatic power up self-test of all important system functions including sensors and display of result on the instrument. Automatic creation of log-file
Calibration|automatic instrument calibration
Network connection|GBit Ethernet with RJ45 connector, external WiFi module
Synchronization|72 channels GNSS synchronized clock, accuracy +/-30ns rms accuracy of 1pps signal, station position is also determined and stored (GPS, Glonass, BeiDou, Galileo)
Standard connectors for 5 channel system|1 x Network RJ45 ruggedized socket(s)
|4 x E-field input terminal 6-pole
|1 x GND terminal
|2 x input terminals for 12V battery protected against reverse polarity
|1 x ext. satellite antenna MCA-Type socket,
|2 x USB2.0 Type A
Case|ruggedized, water-resistant case
Weight|appr. 3.5 kg
External dimensions|25cm x18cm x15cm
Power Input|9V … 15V DC
Power consumption |3.5W – 10W depending on operation mode
Operating temperature range|-30°C to + 60°C
*The system is protected against over voltage; around 16.xx V it should switch off.*
*All components inside the system are industrial (-40°C .. +85°C) grade with the CPUs on the ADB and Clock/GPS even ranging up to 125°C.*
*Lightning protection is up to 1200V, fuses can be exchanged. Above the system will be seriously damaged*
Overview
--------
The ADU-08e-2C comes in a waterproof, ruggedized housing.
The ADU-08e-2C is delivered along with an additional external
GPS-antenna and two battery cables.
Figure 3-2 and 2-3 show the ADU-08e-2C and its operating elements. All
operating elements are numbered and described in more detail in the
following pages.
.. figure:: /media/adu-08e-2C/operating_elements_front_panel.jpg
:width: 80%
:align: center
Operating elements of ADU-08e-2C front-panel
1. USB Socket
2. GPS Status LED
3. Recording Status LED
4. Battery Status LED
5. USB Status LED
6. Job LED
7. System Status LED
8. SD card Slot
9. Button On/Off
.. figure:: /media/adu-08e-2C/operating_elements_right_side.jpg
:width: 80%
:align: center
Operating elements of ADU-08e-2C right side
10. Network socket
11. USB socket
12. Battery sockets
13. E-Field input North
14. E-Field input South
15. E-Field input West
16. E-Field input East
17. Ground input
USB Type “A” Connectors
^^^^^^^^^^^^^^^^^^^^^^^
You will find one USB Type A connector on the front lid and another one
on the left side for connection of USB mass storage devices or USB WiFi
stick. Mass-storage devices and WiFi sticks will be recognized by the
operating system automatically.
GPS status LED
^^^^^^^^^^^^^^
This LED shows 3 states:
.. csv-table::
:delim: |
.. image:: /media/adu-08e-2C/led_off.png|LED off|No GPS synchronization or system in clock hold mode.
.. image:: /media/adu-08e-2C/led_blink.png|LED blink|System has detected sufficient number of satellites, but has not reached the maximum accuracy yet.
.. image:: /media/adu-08e-2C/led_steady_green.png|LED steady green|GPS locked and system fully synchronized.
If the LED is not illuminated despite the GPS-antenna is corrected
properly, it may be that the antenna does not have an open view to the
sky allowing the system to detect at least 4 satellites in track. In
this case it may be helpful to look for another location for the
antenna.
If the ADU has been transferred to another location which is far away
from the last one with a valid GPS lock (more than 300 km), it can take
a while until the system has found a sufficient number of satellites. In
this case the stored Almanac of the satellite positions is no more valid
for the new location and has to be updated first. This procedure can
take up to 15 minutes.
It also may take a longer time if a long time span (more than 1 week)
has been passed since the last GPS fix.
Recording status LED
^^^^^^^^^^^^^^^^^^^^
The red LED is switched on if a data acquisition is running.
Battery Status LED
^^^^^^^^^^^^^^^^^^
In order to get a quick check of the battery voltage without a laptop
connected, this LED is provided. The meaning of the different colors is:
.. csv-table::
:delim: |
.. image:: /media/adu-08e-2C/battery_good.png|Battery good (voltage higher than 12.0V, fully charged)
.. image:: /media/adu-08e-2C/battery_voltage_fair.png|Battery voltage fair (<12.0V and >10.5V)
.. image:: /media/adu-08e-2C/battery_low.png|Battery low (voltage < 10.5 and > 10.0V) shutdown will come soon.
.. image:: /media/adu-08e-2C/system_shutdown_jobs_closed.png|The system has shut down and closed all running jobs automatically.
The exact battery voltage and current are also shown on the status
display and it is monitored in the log file. If the battery voltage gets
low, the ADU will shut-down automatically.
USB Status LED
^^^^^^^^^^^^^^
The LED is switched on if a valid USB mass storage device has been
mounted.
Job LED
^^^^^^^
The LED is switched on if a recording job is pending in the future.
System Status LED
^^^^^^^^^^^^^^^^^
The status LED indicates the actual status of the system it
has 3 different colours:
.. csv-table::
:delim: |
.. image:: /media/adu-08e-2C/battery_good.png|There were no errors detected during system start up and operation
.. image:: /media/adu-08e-2C/battery_voltage_fair.png|Indicates a warning status. The user should check it with the App or the web interface before recording data.
.. image:: /media/adu-08e-2C/battery_low.png|Indicates a severe error of the syste. You must check it with the web interface
Slot for SD card
^^^^^^^^^^^^^^^^
Here an SD card can be inserted. It is used for data storage and can
have a size up to 200 GByte presently. The size delivered on standard is
32 GByte.
Button On / Off
^^^^^^^^^^^^^^^
Pushing this button will start the instrument if connected to a power
source. In order to shut down a running instrument press the button for
a longer time (5 seconds) until you see the shut-down message in the
display. Confirm the shut-down and wait for about 30 seconds until the
ADU switches off.
On a running system this button is also used to activate a dark status
display.
Socket for Network
^^^^^^^^^^^^^^^^^^
The network cable is connected to this socket (RJ45 type).
USB socket
^^^^^^^^^^
A USB device such as USB key or WLAN key can be connected here.
Battery Connectors
^^^^^^^^^^^^^^^^^^
The ADU-08e-2C is equipped with 2 battery sockets. You can connect a 12V
battery or two batteries in parallel for extended operation time. Before
the delivered battery cable can be connected, you have to remove the
protection cap of the socket. The input voltage is 12 V nominal; the
allowed voltage spans from 10.5V to max. 16V.
The inputs are protected against wrong polarity and over and under
voltage. If the ADU should not work, check for wrong polarity or wrong
voltage. If the instrument shall be operated without interruption, you
may use the second battery input to connect a fresh battery. After
having it connected, you may disconnect the old battery from the
ADU-08e-2C for recharging.
Antenna socket for external GPS antenna
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The ADU comes with a built-in GPS antenna which is sufficient for most
cases. We also deliver a second external antenna which may be used in
difficult reception situations or when the ADU is housed in a metal
case. In this case the cable bridge has to be plug into position EXT.
E-field connectors for standard and buffered E-field cable
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
These four terminals are used to connect the standard or the buffered
E-field cables. The plugs on the E-field cable have 6 pins. The center
pin 6 is the pin where the standard E-field cable has to be connected
to. In a typical arrangement the ADU is located in the center of the two
E-field lines. Plug-in the cable connector in a way that the red dots
match on plug and socket and push the plug in until it clicks.
.. csv-table::
:delim: |
**Socket 6-pole ODU MiniSnap G32KON-T06QP00-000 Pin**|**Signal**
1|+12V
2|-12V
3|Sensor GND
4|Sensor GND
5|n.c.
6|Input (+ or -)
.. figure:: /media/adu-08e-2C/Pinning_of_E-Field_Plug-rear_view_(to_solder_cups).jpg
:width: 15%
:align: center
Pinning of E-Field socket (front view)
GND Socket
^^^^^^^^^^
This socket is used to connect the grounding rod or electrode with the
ADU. The grounding can be done by a steel rod or an electrode. Grounding
should be done closely to the ADU.
.. caution::
Grounding of the ADU is very important as otherwise the inputs can
float and may be saturated.
.. include:: ./installation_adu.rstinclude
.. include:: ./reading_data.rstinclude
Declaration of EU Conformity
----------------------------
The ADU-08e-2C complies with all EU standards relevant for this product
(see below).
.. include:: ./terms_and_abbreviations.rstinclude
.. include:: ./safety_notes.rstinclude
.. include:: ./general_notes.rstinclude