Networked vault in Cornwall

June 2006

An engineer from Güralp Systems recently installed a new CMG-3TD sensor with a CMG-DCM, GPS and power management system at a site in Cornwall.

When commissioned, the installation in Cornwall will form part of a new five-station array, all using Güralp Systems' instruments and networking hardware and communicating over VSAT.

The entire station was installed on two site visits with 36 hours.

Installation procedure

Unloading the equipment.

The installation engineer arrived on site at 1800 BST. The complete system was transported in an estate car, including VSAT requipment, network hardware, power systems, two CMG-DCMs and two CMG-3TD systems (one for use as a reference unit.)

All the equipment was unloaded at the vault. The packing box for one sensor was secured to a rope through its carrying straps. The rope was tied off at the top of the access shaft for safety. The packing box was then carefully lowered into the vault. The lowering process was repeated for the second sensor and remaining equipment.

Lowering a sensor into the vault.

The vault was prepared for installation by removing floor coverings in the area to be used for the sensors and cleaning the concrete surface. In the vault, the two sensors were unpacked and connected to the DCM, UPS, and power distribution system. The sensors were left running overnight with the DCM collecting data. The second sensor acted as a temporary reference to verify there were no issues with the vault floor. The next morning, the GPS mast was fixed to the concrete housing for the access shaft. A 28 mm hole was drilled for the GPS cable from the digitizer.

The performance of the two CMG-3TD sensors was compared and a sensor selected. This sensor was installed on the concrete floor of the vault, with polystyrene cladding and a polystyrene cover as thermal insulation. A north/south reference was surveyed at the site and transferred down the hatch to the vault floor, where the direction was marked. The sensor was installed along this line, near one of the vault walls.

The GPS cable from the receiver (above) was connected to the instrument. The remaining equipment was installed on a shelf well above ground level: a CMG-DCM, Güralp Systems 12 V power supply, Ethernet switch, mains power distribution unit, UPS and VSAT module.

Station configuration and usage

The power and data flow layout of the new station is shown in the diagram.

The local network is extended to include the CMG-DCM by use of a VSAT controller and network switch. The DCM can receive data from the instrument and record it, or transmit it over the network.

The site has been allocated 8 static IP addresses, of which 2 are required for network and broadcast addresses and 3 are allocated to installed hardware (network switch, mains power distribution unit and DCM.) Remote operators can access data and configure the installation over a secure connection to the DCM.

The network switch is configured so that site operators can assign one of the 3 spare static IP addresses to a laptop for local monitoring and configuration.

All third-party hardware is powered from a mains supply using a mains distribution unit protected by a UPS. The CMG-DCM receives power from the distribution unit via a 12 V power converter. The CMG-3TD sensor and GPS receiver are powered from the CMG-DCM.

After installation, the VSAT hardware was tested and data flow to Güralp Systems' factory established. The 3TD's remote administration capabilities were verified by initiating a lock/unlock cycle from the factory.

Initial results

The station began operating on 2006-06-08 at 1439 GMT. Data is recorded simultaneously at 1 sample/s and 40 samples/s. Three mass position channels and one channel from an internal temperature sensor are also recorded.

The PSD of the 40 samples/s vertical channel lies within 10 dB of the New Low Noise Model at long periods.

The 1 sample/s vertical channel shows similar performance.



Home Products New installations Customer support About us Latest news The company Addresses and directions Local distributors Vacancies Live seismic activity	Printable version Networked vault in Cornwall June 2006 An engineer from Güralp Systems recently installed a new CMG-3TD sensor with a CMG-DCM, GPS and power management system at a site in Cornwall. When commissioned, the installation in Cornwall will form part of a new five-station array, all using Güralp Systems' instruments and networking hardware and communicating over VSAT. The entire station was installed on two site visits with 36 hours. Installation procedure Unloading the equipment. The installation engineer arrived on site at 1800 BST. The complete system was transported in an estate car, including VSAT requipment, network hardware, power systems, two CMG-DCMs and two CMG-3TD systems (one for use as a reference unit.) All the equipment was unloaded at the vault. The packing box for one sensor was secured to a rope through its carrying straps. The rope was tied off at the top of the access shaft for safety. The packing box was then carefully lowered into the vault. The lowering process was repeated for the second sensor and remaining equipment. Lowering a sensor into the vault. The vault was prepared for installation by removing floor coverings in the area to be used for the sensors and cleaning the concrete surface. In the vault, the two sensors were unpacked and connected to the DCM, UPS, and power distribution system. The sensors were left running overnight with the DCM collecting data. The second sensor acted as a temporary reference to verify there were no issues with the vault floor. The next morning, the GPS mast was fixed to the concrete housing for the access shaft. A 28 mm hole was drilled for the GPS cable from the digitizer. The performance of the two CMG-3TD sensors was compared and a sensor selected. This sensor was installed on the concrete floor of the vault, with polystyrene cladding and a polystyrene cover as thermal insulation. A north/south reference was surveyed at the site and transferred down the hatch to the vault floor, where the direction was marked. The sensor was installed along this line, near one of the vault walls. The GPS cable from the receiver (above) was connected to the instrument. The remaining equipment was installed on a shelf well above ground level: a CMG-DCM, Güralp Systems 12 V power supply, Ethernet switch, mains power distribution unit, UPS and VSAT module. Station configuration and usage The power and data flow layout of the new station is shown in the diagram. The local network is extended to include the CMG-DCM by use of a VSAT controller and network switch. The DCM can receive data from the instrument and record it, or transmit it over the network. The site has been allocated 8 static IP addresses, of which 2 are required for network and broadcast addresses and 3 are allocated to installed hardware (network switch, mains power distribution unit and DCM.) Remote operators can access data and configure the installation over a secure connection to the DCM. The network switch is configured so that site operators can assign one of the 3 spare static IP addresses to a laptop for local monitoring and configuration. All third-party hardware is powered from a mains supply using a mains distribution unit protected by a UPS. The CMG-DCM receives power from the distribution unit via a 12 V power converter. The CMG-3TD sensor and GPS receiver are powered from the CMG-DCM. After installation, the VSAT hardware was tested and data flow to Güralp Systems' factory established. The 3TD's remote administration capabilities were verified by initiating a lock/unlock cycle from the factory. Initial results The station began operating on 2006-06-08 at 1439 GMT. Data is recorded simultaneously at 1 sample/s and 40 samples/s. Three mass position channels and one channel from an internal temperature sensor are also recorded. The PSD of the 40 samples/s vertical channel lies within 10 dB of the New Low Noise Model at long periods. The 1 sample/s vertical channel shows similar performance.