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 compa
red to a high-resolution microconductivity probe. Although noisier than the
thermistor, the thermocouple was found to be stable, to resolve temperatur
e gradients at least 10 times thinner than the thermistor, and to be suffic
iently robust for routine oceanic use.