Thermocouples are used in a variety of cryogenic applications, but special techniques must be employed to approach temperature accuracies of 1% of temperature, even without consideration for the effects of high magnetic fields or high radiation fluxes. The problems are further complicated by exposure to variable gradient conditions at cryogenic temperatures.
Many Lake Shore temperature controllers offer inputs that accommodate most common types of cryogenic thermocouples in use.
Type E (Chromel-Constantan)
Has the highest sensitivity among the three standard thermocouple types typically used at low temperatures (types E, K, and T). The best choice for temperatures down to 40 K.
Type K (Chromel-Alumel)
Recommended for continuous use in inert atmospheres. Has a sensitivity of 4.1 mV/K at 20 K (about ½ of Type E).