CMG-5TD

The new CMG-5TD is a complete seismic station in a sensor case, combining the well-regarded CMG-5T accelerometer with a full-featured CMG-DM24 to form a low-noise strong motion instrument with output over RS232 serial links, modem or (optionally) direct to local area networks over Ethernet.

Features

• Low-noise components for precision and dynamic range
• Full-scale sensitivity from 0.1 to 4.0 g
• Additional high gain outputs
• Low pass corner from 50 to 100 Hz
• Isolated power supply for 10 – 36 V operation
• Completely waterproof and robust; suitable for installation in remote locations
• Compact (205 mm height, 152 mm diameter) and lightweight (3.6 kg) for easy transportation
• Sensor properties identical to the CMG-5T
• All features of a 3-channel CMG-DM24

The new 5TD is already in production, with 25 instruments shipped this month and over 80 currently being built.

Internet Accelerometer

The CMG-5TD Internet Accelerometer option provides a direct Ethernet connection from your instrument.

Using this option, the instrument can serve seismic data to multiple clients simultaneously using the Scream! protocol. This is supported by a number of popular seismic analysis packages as well as Scream! itself.

For maintenance and troubleshooting, a simple Web page interface provides operators with full access to recent status messages and configuration information.

Operators can also download new data from the instrument's internal memory with a single click, or search stored data by stream or date range.

Alternatively, a standard 5TD can output data to a separate Güralp Systems Serial Server (SSU) or Data Communications Module (DCM) with Ethernet or Wi-Fi output.

Other options

• Base plate, fixing ring and bolts for secure mounting
• Direct data download over FireWire or USB
• On-board LCD display allowing operators to monitor triggers and memory usage in real time
• Wireless Internet ("Wi-Fi") support available with separate CMG-SSU unit
• Advanced network and data handling available with separate CMG-DCM unit

Performance

These traces record the 2002 M_w 7.9 earthquake on the Denali Fault in Alaska. Ground movements during this event approached 1 g in amplitude, making it the strongest ever recorded in the Alaskan interior.

The earthquake was recorded at two stations on the Trans-Alaska Oil Pipeline, each around 70 km distant. The pipeline is instrumented with CMG-5TD accelerometers, which combine 5T components with a built-in DM24 digitizer.

Using Güralp Systems' Scream! and ART software packages, the signal can be analysed in a variety of ways. The above graphs show the Fourier spectrum (left in each pair) and response spectrum measured at each of the two sites.

CMG-5 news