drill collar housing 30 further includes a data and power transmission line 54 visible in fig3 that provides electrical power to the sensor modules 46 48 the transmission line 54 also provides a means for data that is obtained by the sensor modules 46 48 to be transmitted to a processor and storage medium which is contained within a neighboring sub a suitable current data and power transmission line for this application is that which is ordinarily referred to in the industry as the u201c m 30 u201d arrangement meaning u201c modem and 30 volts u201d additionally a power and data transmission cable 56 see fig3 is disposed within the body 30 to permit transmission of power and data between the two cavities 42 and 44 electrical plug receptacles schematically indicated at 58 are located on the upper portion of each sensor module cavity 42 and 44 the sensor modules 46 48 each include a plurality of sensors schematically indicated at 60 in fig3 the modules 46 48 also include an electrical plug member 62 that is complimentary to the electrical plug receptacle 58 within the respective cavity 42 or 44 while the sensors 60 are shown in fig3 to be a point source in fact the sensors 60 may be of any configuration and may actually cover a large portion of the surface area of the sensor module 46 or 48 the sensors 60 of each module 46 48 are of a type known in the art for sensing a variety of wellbore or logging conditions hereinafter.