Electronics Installation

All the items necessary to install one vertical element.
The small collection of boxes is everything execpt the vault or borehole required for a vertical short period element.From top left to right, the boxes contain the following:

Once all the boreholes were completed and the grout had cured, the sites were ready for the electronics package installation. All of the required items had been shipped from Dallas, the heavy items such as batteries, boxes and solar panels were shipped by motor freight while the electronics was shipped by air express. SMU technicians carried the seismometers in from Dallas in the back of a light truck. The 18 deep cycle lead-acid batteries dominated the weight of the shipment.

To install the equipment, a 4 person field crew assembled and physically installed the 9 sites in 7 working days. Once the equipment was physically installed, the crew rotated and a 3 people remained an additional week to complete the configuration and initial checkout.

Paul Golden assembles parts of the the element electronics onto a strap which hangs in the borehole. One assembled strap is in the foreground. The blue unit is a digitizer and acquistion unit. The unit to the lower right is the seismometer preamplifier. Paul is connecting the radio modem to the rest of the electronics.

Assembly of the electronics package requires a minimum of tools and expertise and is simple enough to complete in the field. In this case all the borehole electronics packages were assembled in a few hours. The well-head enclosures had been completed during the prior week.

All of the borehole electronics ready for installation.
All 8 of the borehole electronics straps are ready for installation. The 9th package is installed in an surface vault with a three component short period instrument. At the bottom of the strap is the preamp, above it is the digitizer, then the radio modem. The white round units are the GPS clocks.

At this point, all of the seismometers are installed in the borehole vaults, the well head enclosures are attached with the batteries and solar panels. It requires less than an hour at each site to complete the installation of the borehole electronics.

Close-up of a site with all installation and operation components.
In the top left, the borehole electronics strap hangs ready to follow the seismometer down the hole. The radio modem is at the top left corner. The seismometer hangs from a winch assembly, with the hole lock kit on the ground to the right. A telescope for checking the seismometer installation is in the upper right. A small portable laptop computer is used to configure the digitizer and preview the real time data.

The electronics is usually preconfigured prior to installation such that a final configuration may be made from the hub if necessary. A portable laptop computer can record and display short segments of waveform to verify instrument performance, digitizer performance, radio circuit links, and instrument calibration. It also provides text communication back to the recording site. This allows technicians to verify an element is working prior to leaving the site.

Distant photograph of Lajitas element B3.
The element was subsequently fenced with weathered wood to fade into the desert background

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