Table 5. Deviation functions and calibration points for platinum resistance thermometers in the various ranges in which they define T90
a Ranges with an upper limit of 273.16K
Section

Lower Temperature Limit T/K

 Deviation Functions

Calibration Points (See Table 1)

3.3.1 13.8033 2 - 9
3.3.1.1 24.5561 As for 3.3.1 with c4=c5=n=0 2, 5 - 9
3.3.1.2 54.3584

As for 3.3.1 with c2=c3=c4=c5=0, n=1

 6 - 9
3.3.1.3 83.8058

a[W(T90)-1] + b [W(T90)-1]ln W(T90)

 7-9
b Ranges with a lower limit of 0°C
Section

Upper Temperature Limit t/°C

 Deviation Functions

Calibration Points

(See table 1)
3.3.2* 961.78 9, 12-15
3.3.2.1 660.323 As for 3.3.2 with d=0 9, 12 - 14
3.3.2.2 419.527 As for 3.3.2 with c=d=0 9, 12, 13
3.3.2.3 231.928 As for 3.3.2 with c=d=0 9, 11, 12
3.3.2.4 156.5985 As for 3.3.2 with b=c=d=0 9, 11
3.3.2.5 29.7646 As for 3.3.2 with b=c=d=0 9, 10
c Range from 234.3156K (-38.8344°C) to 29.7646°C
3.3.3   As for 3.3.2 with c=d=0 8 - 10
Calibration points 9, 12 -14 are used with d=0 for t90 < or =660.323°C; the values of a, b and c thus obtained are retained for t90 > 660.323°C, with d being determined from calibration point 15