Yes mam, Erika! If you have a line, the "Offset" is the value of Y where the line crosses the Y-axis (the amount that the line is shifted above or below the X-axis when the value of mX = 0).
In PLC scaling, the offset will be the value that must be added to the scaling equation to produce the Minimum Scaled Value when the Input Value = Input Minimum. Here are the scaling equations written in terms of Input Min, Input Max, Scaled Min and Scaled Max:
Scaled value = input value X slope + offset
Slope = scaled max - scaled min / input max - input min
Offset = scaled min - (input min X slope)
For example, suppose I have a Weight Controller that has a range of 0 to 175 pounds per minute. My Input Minimum is 3277 and Input Maximum is 16384. So my scaling equations would look like this:
Slope = (175-0) / ( 16384-3277) = 0.0133516
Offset = 0-(3277 X 0.0133516) =-43.753193
The above says that when the input is 3277 (minimum), then my offset must be -43.753193 so that my controller shows an output of 0 lbs/minute.
And my ladder logic would be like below. You can see that location N30:10 (Loss in Weight) last read a scaled rate of 66 lbs/minute.
(PS: I liked your previous real picture better than that Avatar!)