A Thermocouple Probe for High-Speed Temperature Measurement in the Ocean

A fast-response chromel–constantan thermocouple sensor was constructed for use on the microstructure profiler Chameleon and used for 60 ocean profiles off the coast of Oregon. The stability of the thermocouple was compared to that of an FP07 microbead thermistor, and its frequency response was compared to a high-resolution microconductivity probe. Although noisier than the thermistor, the thermocouple was found to be stable, to resolve temperature gradients at least 10 times thinner than the thermistor, and to be sufficiently robust for routine oceanic use.