Abstract: A thermodynamic housing for a geophysical data acquisition system is provided. The housing includes a novel enclosure cooling system with strategically placed ducting and insulation which maintains proper controller temperature and elevated temperature ambient environments. A novel node enclosure is provided which includes a fail safe 4 bar linkage toggle to ground stakes which enhances physical stability and electrical connectivity.

Abstract: An electrical resistivity tomography system having a novel electrode geometry and method of use is provided. The novel electrode geometry radiates a uniform electric field which produces greatly improved resistivity data.

Abstract: A method for a multichannel geophysical data acquisition system is provided in the field of electrical resistivity tomography. Individual and autonomous node operating systems are provided. Separate communication channels for upstream and downstream data transfer, high voltage transfer and synchronization signals are provided. A novel use of high voltage isolation barriers is also provided. A direct memory access data transfer process is provided.

Abstract: A method for a multichannel geophysical data acquisition system is provided in the field of electrical resistivity tomography. Individual and autonomous node operating systems are provided. Separate communication channels for upstream and downstream data transfer, high voltage transfer and synchronization signals are provided. A novel use of high voltage isolation barriers is also provided. A direct memory access data transfer process is provided.

Abstract: A method of multichannel acquisition and geophysical data is provided. Individual and autonomous node operating systems are provided. Separate communication channels for upstream and downstream data transfer, high voltage transfer and synchronization signals are provided. The method provides for an alternating waveform of injected current to maximize data precision and minimize soil ionization. Node type assignment interleaving is also provided to compress survey time. Self calibration of nodes is provided as is self addressing of a node array.

Abstract: An architecture for a multichannel geophysical data acquisition system is provided in the field of electrical resistivity tomography. Individual and autonomous node operating systems are provided. Separate communication channels for upstream and downstream data transfer, high voltage transfer and synchronization signals are provided. A novel use of high voltage isolation barriers is also provided. A direct memory access data transfer process is provided.

Abstract: A dual roller powder spreader assembly for use in layerwise manufacture in a powder bed fusion additive manufacture process utilizes in an embodiment tilting of the dual roller assembly such that a lead roller is raised upwardly relative to the powder bed in a sweep. This is accomplished using a mechanical cam-like engagement initiated at each end of the assembly's travel, causing what will then be the lead roller to rise as a whole relative to the now following roller, the latter pushing the powder pile across the powder bed. The tilt process is reversed at each end of travel.

Abstract: A dual roller powder spreader assembly for use in layerwise manufacture in a powder bed fusion additive manufacture process utilizes in an embodiment tilting of the dual roller assembly such that a lead roller is raised upwardly relative to the powder bed in a sweep. This is accomplished using a mechanical cam-like engagement initiated at each end of the assembly's travel, causing what will then be the lead roller to rise as a whole relative to the now following roller, the latter pushing the powder pile across the powder bed. The tilt process is reversed at each end of travel.