presents the transient response of the microthermocouple
placed in the vacuum measurement chamber. At
the end of the heating period t
h
2
, the temperature of the Th
micro-thermocouple tends to that of the fluid temperature T
.A
temperature calibration apparatus (AOIP PHP 601) is used to cali-
brate the thermocouple with a global static temperature accuracy
of 0.1 K in the temperature range 293 Ke400 K. The time t
necessary to the sensor during the cooling phase to reach the
temperature T
is not constant and depends on the fluid pressure P
directly. During this time, the wires of the thermocouple exchange
heat with the environment under the static pressure P to be
determined. The action of the fluid is then traceable only during
f
this cooling phase