Manganin sensors as low temperature pressure gauges

The pressure coefficient of the resistance of manganin sensors was studied in the temperature range 55 K - 350 K. A He-gas pressure system was used to maintain fully hydrostatic conditions at low. temperatures. The pressure c oefficient was determined from isothermal pressure dependencies of resistan ce measured at various fixed temperatures. The obtained results were verifi ed by isobaric measurements carried out as a function of temperatures at se veral fixed pressures. The pressure coefficient has a minimum at 114 K, abo ut 5% lower than the room temperature value. Below and above 114 K it can b e well approximated by linear dependences: alpha (T)/alpha (298 K) = 0.9913 - 3.35543 x 10(-4) T and 0.9208 + 2.2623 x 10(-4) T, respectively.