Question

An iron–constantan thermocouple is to be used to measure temperatures between 0 and 400°C. What will be the non-linearity error as a percentage of the full-scale reading at 100°C if a linear relationship is assumed between e.m.f. and temperature? e.m.f. at 100°C = 5.268 mV, e.m.f. at 400°C = 21.846 mV

Answer 1

-0.89%

Step-by-step explanation:

Assuming a proportional relationship between EMF and Celsius temperature, the measured value of EMF at 100 °C will be interpreted as a temperature of ...

T/5.268 = 400/21.846

T = 5.268(400/21.846) ≈ 96.457 . . . . °C

The error as a fraction of full scale is ...

(96.457 -100)/400 × 100% ≈ -0.886%

The error at 100 °C is about -0.89% of full scale.