摘要 |
A temperature controlled probe assembly (58) for measuring log temperatures in a furnace (10) for heating metal logs (20) includes a carriage (88) selectively movable by a pneumatically controlled air cylinder (64). The carriage (88) includes a barrel (92) having an air chamber (102), a pair of thermocouple probe rods (40, 42) extending through the barrel (92), and cooling air channels (126) opening into the air chamber (102) for supplying air to cool the probes (40, 42). Another thermocouple (94) measures the temperature of the environment surrounding the thermocouple probe rods (40, 42) and a cooling air regulator (160) is selectively actuated when the temperature of the probe environment is greater than a predetermined temperature. The regulator (160) varies the amount of cooling air supplied to the probe rods (40, 42) in accordance with the amount of combustion air being used by the furnace (10).
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