Thermocouple reference tables based on the IPTS-68 :

A Computer-Automated Temperature Control System for Semiconductor Measurements.

“…The lower reference junction is immersed at all times in liquid nitrogen which is at its boiling point, 77.348 K, according to the International Practical Temperature Scale adopted in 1968 (IPTS-68). [4] The type T thermocouple is the only one of the standardized types for which limits of error are set below 00 C. The thermocouple wires -used in this temperature control system are specified by the manufacturer (Claud S. Gordon Co., Richmond, IL) to meet the special limits of Kelvin. Function TEMP converges in less than seven iteraticns.…”

Thermal-performance study of liquid metal fast breeder reactor insulation

“…Good agreement is obtained between the meter and the thermocouple reference tables by Powell (1968). Model 15 is calibrated at 100 0 *F (538 C) full scale in a similar manner using a voltage generator.…”

A practical test of the air density equation in standards laboratories at differing altitude

“…First, 13 thermocouples in seri es were disposed about th'e weighing ch amb er. Type E [4] th ermocouples were chosen in order to achieve maximum se nsitiv ity at room temperature. The reference junctions of th e thermoco uples were thermally anchored around a massive copper block which was itself surro un ded by 8 cm of th er mal insulation.…”