This article gives some results of experimental work carried out at the Bakinsk Structural-Materials Combine with the aim of obtaining current information on the average-mass temperature of the materials and showing the dependence of the average-mass temperatur e and the temperature of the kiln atmosphere (effluent gases) on the fuel consumption. The experiments were carried out in a tunnel kiln designed for firing ventilation blocks and 200-mm diam. sewage pipes. The kiln was 75-m long and had a channel width of 3 m; the burners were arranged along the sides (15 on each side). The kiln has 25 working positions: heating zone (Nos. l-9),firing zone (10-17), and the cooling zone (18-25). The fuel used is natural gas. The maximum firing temperature is 980~ Every 1.5 h, the carriages with the articles for firing ate pushed along; the firing lasts 37.5 h. The burner flames on both sides of the furnace fall on the center of the carriages and on the joint between two neighboring carriages. The gases are removed at the beginning of the kiln. To carry out the study, an experimental carriage was made measuring 3 x 3 x 1.5 m. The height of the load was 1.25 m. In order to determine the character of the distribution of temperature across and in a vertical direction to the articles being fired, eight Chromel--Alumel thermocouples were mounted on the experimental carriage. The thermocoup!es were arranged roughly in three planes (planes a, b, and c in Fig. I). These levels were at a height of 200, 600, and 900 mm from the surface of the carriage lining. The junction of the thermocouples was placed at a depth of 10-15 mm in the body of the articles to be fired. An additional thermocouple was mounted at a height of 1350 mm from the bottom of the carriage (thermocouple 9) in order to provide continuous monitoring of the temperature of the kiln atmosphere over the whole route of the first articles. The working junction of this thermocouple was in the space between the surface of the articles being fired and the crown of the kiln. In order to transmit the thermo emf to the measuring instrument, we used a telemetric system with step-by-step selectors whose transmitting part was mounted on the experimental carriage while the receiver was placed at the instrumentation point. The step-by-step selectors were synchronized at an interval of approximately 30 sec thus ensuring that the free ends of the thermocouple were switched alternately to the secondary instrument (electronic potentiometer) with a simultaneous indication of the number of the thermocouple.