Commercial platinum resistance thermometers are often manufa

Commercial platinum resistance thermometers are often manufactured with a resistance of 100.0 at 0.0 ºC. The temperature coefficiente of resistivity is 3.9 x 10^-3/ºC. If the resistance of such a thermometer reads 109.8 , what is the temperature?

Solution

Accotding to the given problem,

Temperature Variation on resistance,

R = R₀[1 + T], where R₀ = intiail reistance, = temperature

coefficiente of resistivity, T = temparature change

R = final resitance.

As from the problem, R₀ = 100 at 0ºC, = 3.9 x 10^-3/ºC , R = 109.8 T_i= 0ºC and find T_f

109.8 = 100 [1+3.9*10^-3(T_f - T_i)]

1+3.9*10^-3(T_f - T_i) = 1.098

3.9*10^-3(T_f - T_i) = 0.098

T_f - T_i = 25.128ºC

T_f = 25.128ºC