FT-1A-T

This is a fast-response temperature sensor for measurement of the sensible heat flux when combined with a sonic anemometer.  ISFS (then ASTER) only had 3 electronics bridges to support these probes.  The probe consisted of a length of fine platinum wire stretched in a coil on a bobbin supported by non-conductive fibers.  It had a "double time constant" due to the length of the wire and the fiber spacing.  Wire breakage in the field was also an issue.  Retired many years ago when sonic anemometers began to have reliable temperature (albeit virtual temperature) measurements.  Superceeded during CFACT (2022) by the use of fine-wire thermocouples.

Report on ISFS's use of the AIR sensors.