Abstract: The loading car (25) transfers the batch and deposits it on the plug (10) of the furnace (1).The batch is introduced into the furnace (1) and the latter is closed by means of the lift (12) which is lowered after the treatment to an intermediate position, from which moment the furnace (1 ) can be displaced horizontally, the lower belt (4) pushing the grid at the bottom of the batch over the cover (17) and the platform (22) of the lift (18) being in the upper position. The cover (17) ensures the imperviousness of the furnace opening to the gases protecting the batch.This lift allows the batch to be introduced into the hardening vat then brought back into a drain position and deposited on the unloading car (38) which moves along the track (36, 37).

Abstract: To make it possible to exchange the solid-electrolyte ball (1) easily and quickly, while at the same time ensuring effective sealing between the support (3) and the ball (1), when it has been polluted by the atmosphere of a furnace, the probe comprises a sleeve (4) communicating with the atmosphere of the furnace via orifices (13) and having a stop (5) forming a measuring electrode. The ball is stressed up against the stop (5) by a support (3), while a shoe (12) pressed against the ball (1) by a rod (9) forms an internal electode. This rod (9) has a cavity (15), in which is accommodated a thermocouple (16) for measuring the temperature of the ball (1), and longitudinal ducts for the passage of wires (18, 19, 24) for connection to the thermocouple (16) and the shoe (12) and for conveying reference air into the region of the shoe. The spherical shape of the contact surface between the ball (1) and the support (3) ensures effective sealing.