GEO-A200 Compact Digital Accelograph

• FBA based compact digital accelerograph
• Cost effective and high performance
• Bandwidth DC-200Hz
• Dynamic range >155dB
• Ethernet - WiFi - Serial port
• 32bit ADC digitizer
• GNSS time/Precision DPLL
• 0.1-1000 samples per second
• LCD and six status LEDs
• Integrated Seismic Switch
• Embedded open-source OS
• Embedded seedLink server
• Embedded earthworm server
• Continuous and trigger recording
• Advanced networking functionality
• Smart seismic network operation

DIGITIZER

• Analog channels: 3 seismic (acceleration) channels

• A/D converter: Fourth Generation, Delta-Sigma, 32bits data stream, one per channel

• THD: 125dB

• Modulator: Fourth Generation, 4th order Delta-Sigma Modulator

• Filter: Programmable SINC, FIR, IIR filtering, auto-calibration function

• Filter Response: Selectable Minimum or Linear Phase Filter

• Sampling Rate: 1–1000 sps, optional 0.1–1000 sps

• Power: 9–18Vdc, <2W

• Dynamic Range: >140dB@100sps, 128dB@1000sps

DATA RECORDING

• Storage Media: MicroSD flash card, removable USB stick, RingBuffer RAM storing 10hr+ data, MiniSEED data files

• Information file: System log file, SOH message

• Recording mode: Continuous, Triggered STA/LTA based or both. MiniSEED Files

• Operation: Advanced functionality if connected to an Earthworm server

• Operating System: Open source based, ability for custom application run

• Memory: Internal 256Mbyte RAM ring buffer, modern and minimum 64Gbyte FLASH memory, min 8Gbyte internal FLASH

• Trigger time: Pre and post trigger time >30 sec, user selectable

TIME BASE

• Type: GNSS receiver (GPS, GLONASS, WAAS, EGNOS, Beidou, GZSS) / PDDL GPS port, up to 30m cable GPS antenna or 10m active GPS antenna

• Accuracy Time: +/-1μsec to UTC on time pulse, +/-5 meters to position

• Timing Sources: Ultra low drift DPLL unit using TCVCXO, RTC

• DPLL drift: DPLL drifts less than 1.7μsec between one hour GPS cycles

• Specifications may change to better values without notice.

COMMUNICATION

• Connectivity: Ethernet port, WiFi, or Serial Port (*), Seedlink and Earthworm server, low latency 0.1 sec

• Protocols: Protocols SSH, FTP, SFTP, Web Interface, TCP/IP, HTTP, HTTPS, PPP, MQTT, CoAP/CoAPS, NTP

• LCD: Miniature LCD with interface information messages

• LED: Six high brightness LEDs

CALIBRATION

• Control Signals: Automatic or on demand centering (offset removal)

• Calibration: Pulse, Sine waveform, variable amplitude and frequency, 16bit DAC

INTEGRATED ACCELERATION SENSOR

• Axes: Three, orthogonally placed

• Bandwidth: DC – 200Hz

• Dynamic Range: >155dB, >160dB@1Hz/1HzBW

• Full Scale Range (g): +/-4.2, 1.0, 0.5, 0.25, 0.125, 0.075g

• Noise: Below ALNM between 3s–10Hz

PHYSICAL

• Size: 139mm height, 138mm diameter

• Weight: 2.8kg

ENVIRONMENTAL

• Temperature range: -20 to +70°C

• Humidity: 100%, IP67 enclosure

EMERGENCY

• Seismic switch: SPST type Relay, 1A switch

• Connection: GUI with interface configurable, threshold limit readable

• Reference: () = Optional*