The Linear Equation Resistance and Temperature

Draw a graph by plotting the two points and joining the dots or apply O level maths, any text book should be able to tell you how to obtain the equation from two points.
Why do you need an equation?
Del

This is quite simple really.

Taking the start datum (zero on the scale) of 100 ohm = 20C, and full scale as 180 ohm = 120C, we can see that for a change of 80 ohm in resistance, we get a change of temperature of 100C. So the ratio (slope of the line) = 100/80 = 1.25

Allowing for the offsets, for any given value of resistance (ohm), the corresponding temperature will be :- Temp= ((Resistance-100)*1.25)+20

Please try it by drawing the graph as suggested, and then give me a gold star from your teacher :)

Well explained, (and more patience than me)
Del

So we have become a free homework service for lazy engineering students? What are we teaching them? How to become managers and get someone else to do everything for you?

This is such a simple question I assumed it came from school - my kids did this aged 11/12. I hope my explanation helps them to understand the concept of zero, span and offset, and one day they may go on to study engineering.

If this is really from college/university then they will struggle with PID calcs.