Earth Data EDR-217 Digitizer Specification

No. of channels 4 or 8 differential input
Input impedance 1 MΩ (any input to ground)
Input CMRR Better than -100 dB
Number of gain ranges 4 (very low gain; low gain; high gain; very high gain)
Input sensitivity 20 nV, 100 nV or 2.5 µV per bit (24-bit word size)
Input range ±0.16 V, ±0.8 V, ±20 V user programmable
Gain accuracy Within 0.1 dB after auto-calibration
D.C. offset ±5 µV low gain and very low gain; ±1 µV high gain.
Offset drift ±10 µV per °C
± 250 nV per °C (with optional temperature compensation)
Crosstalk Better than -120 dB
Number of A to D converters 4 or 8 (one per channel)
Type Earth Data proprietary Delta Sigma Converter
Sampling frequency 192 KHz
Filter type

Linear phase

Minimal phase

Alias protection Spurious in band signals better than -120 dB as a result of any frequency above the passband and any amplitude up to full scale.
Primary sample rates 1, 2, 4, 5, 10, 20, 25, 40, 50, 75, 100, 120, 125, 150, 200, 250, 300, 375, 500, 600, 750, 1000, 2000, 3000
Secondary sample rates As above (4 channel unit); Sub-division of primary rate (8 channel unit)
RMS to RMS noise 150 dB below 10 Hz
140 dB below 100 Hz
125 dB below 1000 Hz
Analogue response d.c. to 0.4 of selected sample rate
Spurious tones Nothing above -160 dB (input short circuit)
Intermodulation products Less than -120 dB for any two sine wave frequencies within the passband at half full scale amplitude.
Timing accuracy Better than ±10 µs (GNSS locked)
Sensor power +12 V ±0.2 V available on input connector. (100 µA current limited)
Number of channels 4 plus 3 on each input connector (total of 7 on a four channel unit; 10 on an eight channel unit)
Type of conversion Multiplexed successive approximation; 16 bit
Input range ±10 V
Sampling Rate 1 Hz
Available interfaces Ethernet; RS232; RS485; USB
Internal storage Onboard FLASH, Buffer size and Data Logger capabilities enabled by fitting internal Micro SD card (typically 32 GB, larger capcities are available if required). Data files typically stores as Mini-SEED.
Secure sockets SSL, SSH.
Application protocols SEEDLink, CAPS, MODMAN.
Real-time data latency <0.5s
Sensor control 4 auxilary outputs (mass lock, mass unlock, mass center with automatic monitoring support, calibration enable) configuration as TTL or Open Collector (to 50V)
Sensor calibration Sine Wine, Square Wave (Pulse), White Noise (all configuration)
GNSS Internal with external option available
GNSS constellations GPS, GLONASS, Galileo and BeiDou (configurable as standalone or concurrent combinations)
GNSS augmentation systems SBAS (WAAS, EGNOS, MSAS and GAGAN), QZSS and IMES (configurable)
Housing Extruded alluminium
Water proofing To IP67 standard (water only)
Operating temperature -20 to +60 °C
Storage temperature -40 to +80 °C
Supply voltage range 10.5 V to 28 V
Power consumption 500 mW (no comms 4 channel unit); 1.2 W (ethernet, 4 channel unit); 1.5 W (ethernet and USB. 4 channel unit)
Dimensions Length: 103 mm; Width: 108 mm; Depth: 45 mm;
Weight 0.75 Kg

This specification is subject to change without notice.