Abstract: The detector of metalliferous objects comprising an electrically coupled to an alternating voltage generator driving loop, rigidly fitted to two pairs of receiving loops, positioned at opposite sides of the driving loop, coaxial and parallel to one another. The receiving loops are connected to connected in series balancers, differential amplifiers, electric signal compensators with the control inputs thereof connected to the generator, selective amplifiers, data processors, logic OR gate, and signalling unit.

Abstract: A machine for continuous flash butt welding comprises control devices for the control of beginning-of-upset operation and upset value, respectively, and such control devices are provided in one unit (a computer). Also provided are a control device for automatically controlling the flashing-off speed and a welding current meter connected to a welding transformer. A sensor connected to the meter detects short-circuit duration in the welding circuit in response to outputs of a welding control enabling signal generator actuated at the final stage of flashing and in the course of upsetting. The inputs of the latter are coupled to the computer and the output is connected to an upset value deviation control circuit. The latter receives inputs from a circuit which detects slippage of the parts in the clamping jaws during welding. The upset value deviation control circuit is further connected to a sensor means for detecting misalignment of a rod of the follow-up slide valve relative to its body.