The Magnetic Resonance Imaging Logging (MRIL) tool is a centralized tool that provides porosity and other petrophysical parameters related to the overall productivity of hydrocarbons in the downhole environment. The tool does this by measuring hydrogen atoms located within a thin-walled, cylindrical-volume concentric to the axis of the tool. The main components of the tool consists of a strong permanent magnet, which produces a gradient magnetic field used to polarize hydrogen atoms, and an antenna which both transmits a Radio Frequency (RF) signal and receives an echo response.

It receives the command download by the surface system, then transmit this command to the logging tools after decoding. It also can code and amplify the data from the logging tools and upload it to the surface system. Meantime, multiple analog could be acquired.

CLASS is the operation software for EXCLL2000 logging system produced by HALLIBURTON. At early it installed on UNIX workstation, later mounted in laptop for the use of the portable surface system. It can be used for real time logging services, playback etc.

When connected with code wheel, it can acquire the rotation turns of the code wheel by measuring the pulse count. Then calculate the length by the wheel perimeter. When connected with tension meter， it can acquire the surface tension value by analog acquisition and A/D conversion.