ESPCD Introduction
The 3ESPCD is a 60-second triaxial weak motion seismometer with an integrated CMG-CD24 digitizer. The compact size and moderate weight (8.3kg) makes it more portable than the the 3T or 3TP. The 3ESPCD has mass locking, unlocking and centering. Data can be directly downloaded from the instrument to an external hard drive via a firewire cable with a waterproof milspec connector. This can be performed whilst the instrument is buried.
The ESPCD has a new type of transfer function which creates high clip levels at high frequencies and a low noise floor at long periods, allowing one to use the dynamic range of the instrument more effectively. This type of instrument is most suitable for the study of body waves and shorter period surface waves.
Much of the information presented in this page is from Guralp.
Specification
| Total number | 51 |
|---|---|
Digitizer |
Integrated CD24 digitizer |
Masses |
Three Orthogonal masses (XYZ). Automatic mass locking, unlocking and centering (within 2 degrees from the horizontal) by remote terminal command or via Scream! |
Tilt range |
±2.5° |
Data output |
GCF format to internal flash |
Memory |
8Gb or 16Gb of internal flash memory allowing approximately 120/240 days of recording three channels at 100 sps. |
Data download |
Data can be moved from the internal flash memory to an external hard-drive via an IEEE1394 (firewire) port and cable. |
System control |
Instrument control is via Guralp software available on Windows and Linux platforms. |
Power consumption |
1.6W (hourly cycled GPS) 1.8W (continuous GPS) |
Power supply |
12V (10-28V DC range) |
Dimensions |
Height: 350mm (with feet and handle); Diameter: 176mm |
Weight |
9.3 kg for sensor alone |
Frequency response |
60sec to 50Hz |
Sampling rate |
1-1000sps |
Operating temperature |
-20°C to 65°C |
GPS |
External GPS antenna |
Shipping information
ESPCDs ship in boxes containing 1 instrument, 1 GPS external antenna and all associated cables.
Most projects use one or two 20W solar panels per instrument, details of which can be found on the power in the field pages. 12V batteries (usually car batteries) should be provided by the user.
SEIS-UK is able to offer advice on the appropriate number of solar panels and batteries necessary for your period and latitude of deployment.
| Instrument box dimensions | 530mm x 400mm x 570mm |
|---|---|
| Instrument box volume | 0.121m3 |
| Instrument box weight | 20kg |
| Solar box dimensions | 720mm x 520mm x 390mm |
| Solar box volume | 0.148m3 |
| Solar box weight (5 panels) | 32kg |
Links and Downloads
Guralp's operations manual for the CMG-3ESPCD
Guralp's CMG-3ESPCD data sheet