The pneumatic temperature monitoring system for the Experimental Gas-Cooled Reactor (EGCR) is designed to measure individual fuel channel coolant temperatures during the reactor lifetime. The pneumatic system is superior to a fixed thermocouple system if it can be maintained to operate with the desired accuracy, throughout the reactor lifetime. The initial cost of the pneumatic system, when integrated with the burst fuel element detection system, is less than that for an equivalent replaceable thermocouple system. The in-reactor portion of the pneumatic system is being installed during initial construction of EGCR as a backup for a fixed thermocouple system. The remainder of the system may be installed after initial reactor operation, to determine whether long term operation and maintenance is economically feasible.