Question

A tungsten resistance thermometer with a range of –270 to +1100°C has a quoted inaccuracy of ±1.5% of full-scale reading. What is the likely measurement error when it is reading a temperature of 950°C?

Answer 1

Over the range means over 1100-(-270)=1370 degrees.

The error of ±1.5% applies to the whole range, so that’s ±1.5% per 1370 degrees, or ±1.5/1370=±0.001095% per degree.

At 950 degrees, the error is ±950*0.001095=±1.04% or ±0.0104.

In absolute terms is 950±9.88 degrees.