The Scientific Instruments Aerospace Temperature Probe Series 44B is a platinum-resistance temperature probe utilized for space missions.

It is designed to permit the interchangeability of units with the same number.

The probe's sensing element is annealed and strain-free platinum wire supported and contained in a closed well housing. Its housing is made of 316 stainless steel.

The unit can operate in mutiple gaseous or liquid mediums, which are compatible with the sheath-housing material and within the temperature range of the unit. It is capable of withstanding 20 mA continuously or 60 mA peak commutated at 10 Hz without damage.