Key points are not available for this paper at this time.
The thermionic emission from thoroughly outgassed platinum in high vacuum has been measured to one-half percent over the temperature range 1360 to 1750^, the temperatures being measured by careful optical pyrometry. The values obtained for the thermionic constants of the T^2 law are, when corrected for the Schottky effect, b=72, 820^K, =6. 27 volts, A=17, 000 amp/cm^2 deg^2. The value of is possibly in error by not more than 1 percent because of uncertainties in the temperature scale, and agrees within one-half percent with the value of the photoelectric work function previously obtained. The data confirm the previous announcement that for clean platinum A is 250 times greater than the theoretical value of 60. 2 amp/cm^2 deg^2.
Lee A. DuBridge (1928) studied this question.