known well logging sensor or instrument that can be moved through the inside of a tube or conduit may be used with a deployment device according to the invention such sensors and or instruments include without limitation acoustic sensors electromagnetic resistivity sensors galvanic resistivity sensors seismic sensors compton scatter gamma gamma density sensors neutron capture cross section sensors neuron slowing down length sensors calipers gravity sensors and the like the fluid pressure pulse device 18 has a variable flow restriction not show which is controlled by electric signals transmitted by the ft tool 14 to the pressure pulse device 18 which signals represent part of the data produced by the ft tool 14 during the making of measurements of the earth formation 2 the upper end of the deployment device 12 a may be provided with a latch 20 for latching of an armored electrical cable not shown to the device 12 a for retrieval from the bottom of the drill string 9 a wellhead 22 is typically connected to the upper end of the casing 4 and is provided with an outlet conduit 24 terminating in a drilling fluid reservoir 26 provided with a suitable sieve means not shown for removing drill cuttings from the drilling fluid a pump 28 having an inlet 30 and an outlet 32 is arranged to pump drilling fluid from the fluid reservoir 26.