EDR-210 Recorder Description

The EDR-210 Portable Field Recorder provides three or six independent channels of extremely high dynamic range at rates of 1 to 3,000 Hz. A selectable conversion word size of up to 32-bits is available for fully representing the high dynamic range.

SIGNAL TO NOISE

A signal to noise ratio of typically 142 dB is achieved at a sample rate of 100 Hz falling to 125 dB at 1,000 Hz using a 24-bit word. 150 dB is obtained below 10 Hz when a 32-bit word size is selected.

The signal bandwidth is always d.c. to 0.4 of the selected sample rate (± 0.1 dB) with over 140 dB of rejection above the half sampling frequency negating any requirement for anti-alias filtering.

SIGNAL INPUTS

Three or six channels of fully differential high resolution inputs are available. Common mode rejection is better than 100dB. One of four sensitivity settings can be selected. Up to ± 20 volts can be accommodated on the least sensitive setting, with one bit representing 20nV on the most sensitive setting. Eight additional low resolution channels can be recorded at low sample rate for monitoring external parameters on the three channel version, dropping to four on six channel units.

CONVERTERS

The converters use a 7th order Delta Sigma technique developed by Earth Data. In addition to their high dynamic range they are also free from spurious tones and artefacts present in alternative designs.

TIMING

The unit can be operated using one of three GPS modes. The default, which can be used if there is a clear view of the sky, employs the internal antenna. Alternatively, an external antenna can be attached and sited up to 20 metres from the EDR-210. In extreme cases a remote GPS unit can be attached, which can be up to 1km from the EDR-210. Power cycling can be used in all three modes for additional power saving. Alternative time sources, such as NTP time servers can be used.

STATUS

Power supply voltage, current and internal temperatures are continuously monitored and reported.

CONNECTION & INTERFACES

he EDR-210 can be configured and monitored via any standard HTTP web browser. In addition, it can also be configured as a SeedLink server enabling communication with external seismic systems. The internal mass storage media can be employed to store data in Mini-SEED format, or alternatively external mass storage units can be directly connected via USB. The unit supports the FTP and RSYNC protocols should remote users wish to download / synchronize any stored data files.

ENVIRONMENTAL

The EDR-210 is housed in a moulded ABS enclosure. Operating temperature range is -20°C to +60°C.