The dual function sensor (DFS) is intended to provide concurrent and coincident measurements of temperature (1.5 K to 400 K and 0.1 K to 400 K) and magnetic fields (up to 30 T). The DFS approach can be applied to the problem in cryogenic thermometry of temperature measurements in high magnetic fields, since, by simultaneous, direct measurements of temperature and local magnetic field, and knowledge of the field sensitivity of the thermometer it is possible to compute a correction for the field effects on the thermometer, and to provide in a compact way both temperature and magnetic field information.

The DFS consists of a Ge-on-GaAs film resistance thermometer and an InSb-on-GaAs film Hall-effect magnetic field sensor combined in a single package with dimensions 3.5 mm wide, 2.2 mm high and 10.1 mm long. At constant current the Hall sensor provides an output voltage proportional to magnetic field induction. The DFS has eight copper contact leads: four leads for the thermometer and four leads for the Hall sensor.

Two models of the DFS have been developed and produced for use in the 1.5 to 400 K (DFS-1) and 0.1 to 400 (DFS-2) temperature ranges.

Typical resistance and sensitivity (S=dR/dT) vs. temperature curves for DFS-1 and DFS-2 thermometers that are intended for operation in the 1.5 K to 400 K and 0.1 to 400 K temperature ranges, respectively

InSb-on-GaAs film Hall-effect magnetic field sensor characteristics

  Operating temperature range.........................................1 to 400 K
  Input resistance...........................................................10 to 20 Ohms
  Output resistance.........................................................15 to 30 Ohms
  Rated control current....................................................0.5 mA
  Magnetic sensitivity (at rated control current)..................5 to 6 mV/Tesla
  Zero field offset voltage (at rated control current)............0.1 mV (max.)
  Temperature coefficient of magnetic sensitivity................0.03 %/K (max.)

L I T E R A T U R E

 
1. V.F.Mitin, N.S.Boltovets, V.V.Kholevchuk, V.V.Basanets, E.V.Mitin, P.C.McDonald, F.Pavese. Dual function sensors for concurrent measurements of temperature and magnetic fields in cryogenic applications. Cryogenics, Vol. 48, pp. 413-416 (2008).

 
2. Â.Ô. Ìèòèí, Â.Â. Õîëåâ÷óê, È.Þ. Íåìèø, Å.Â. Ìèòèí, Í.Ñ. Áîëòîâåö. Òåðìîìåòðû ñîïðîòèâëåíèÿ è ìíîãîôóíêöèîíàëüíûå ñåíñîðû äëÿ îäíîâðåìåííîãî èçìåðåíèÿ òåìïåðàòóðû è ìàãíèòíîãî ïîëÿ. Íîâûå ïðîìûøëåííûå òåõíîëîãèè, ¹ 5, ñ. 29-33 (2008).



Back