22

gDAS-32

Technical Specifications

2 input channels
• Independent 32 it analogue-digital converters
• Input voltage range: +/- 2.5 V (modifiable to +/- 26 V)
• Maximum continuous input voltage limit: +/- 50 V
• Maximum momentary input voltage limit: +/- 500 V
• Input impedance: 20 MΩ
Maximum number of samples per time series record: 4 million [2    ] samples
Sample rate
• User programmable
- Maximum fs: 32 kHz, Time series record length = 128 secnds
-Minimum fs: 8 Hz, Time series record length = 145 hours
• Typical fs for MT acquisition:
- 32 kHz, each time series record length = 128 seconds
- 2 kHz, each time series record length = 34 minutes
- 128 Hz, each time series record length = 9 hours
• Typical fs for IP acquisition:
- 512 Hz, each time series record length = 2 hours
GPS synchronization
• Maximum GPS error: 100 ns
• Typical (measured) GPS error: 10 ns
Calibration
• Internal signal generator. +/- 20.48 mV, 0.5Hz for internal calibration and system check
Contact impedance
• Measured prior to each acquisition and on user command
Memory / Storage
• Internal pen drive: 8 Gb provides for 200 typical time series filed
• Typical time series file (2 channels, 4 M samples): 35 Mb
• Time series data files: simple 32-bit binary
• Data download: USB cable or removal of pen drive
• Data available for download during acquisition and turned off
Processors
• Real time acquisition processor Microchip 32-bit 80 MHz
• HMI Processors 32-bit ARM 200 Mhz with light Linux kernel
Power source
• External battery: 9 to 22 V
Battery type according to application with/without solar panel
• Consumption during acquisition:
- Bluetooth on: 200 mA (12 V supply)
- Bluetooth off: 145 mA (12 V supply)
- XBee external radios: to be defined

General Specifications

Dimensions & weight
• External Pelican case with connectors
- 215 x 175 x 100 mm, 1.2 kg
• Internal electronics and housing
- 190 x 124 x 45 mm, .4 kg
 
User interface
• No screen or buttons
• 2 powered RS232 ports, 9600 baud rate
- Internal port for Bluetooth
- External port for XBee (or similar) radio
- Output compatible user-friendly real-time text updated at 1 Hz with status information
- Other comms:
User can send real-time commands (start acquisition, abort, calibrate, contact resistance, etc)
Receive 3-day history of acquisition and system information
Receive a 30s record of binary fs = 256 Hz time series data (non-terminal compatible)
• Schedules (acquisition & communication) and ADC configuration
- User updated by copying a text file to the USB and rebooting gDAS32