“…T A = 100°C in the calculations for Table 2. The choice of T A is arbitrary, but it can be shown that any value of ir, in the range 100-140°C results in a similar value of the ratio (tRl/tR2)1000 f Levine (1956), (b) Deindoerfer (1957), (c) Klostergaard (1965), (d) Ball & Olsen (1957), (e) Stumbo, Murphy & Cochran (1950), (f) Knock (1954). …”