AbstractA multipoint, vessel-temperature monitoring system is developed for a large reversed-field pinch machine, the TPE-RX at the Electrotechnical Laboratory. It consists of a total of 268 thermocouples attached mainly on the outer surface of the vacuum vessel and a multipoint, stand-alone data acquisition system. Simultaneous data sampling for all the signals every 0.5 s is possible with the data acquisition system dedicated to this purpose. This system is used to clarify the spatial distribution of the heat load on the first wall around a torus from a magnetically confined plasma. The entire system is currently used in routine operations and has been proven to be very effective for the detection of a localized plasma–wall interaction due to plasma distortion. Details of the specifications, characteristics and typical examples are reported.