Hi Wyn. Thanks for taking the time and interest to help.
I'm afraid the solution suggested will not work. If the Tolerance is exceeded by the actual measurement, I only need to see by how much.
If I may, think of it this way;
I have a flat surface, where the measurement point on that flat surface is 0cm. I then place an object on top of that flat surface, I measure the height, this is 3cm. Similarly, I place an object underneath this flat surface, I measure the negative height, -3cm. In both instances, the formula I seek should return a "0" value because each measured height is within the 10cm tolerance range, ie +5cm through -5cm. I have a problem with formulating the negative part of the formula, vis instead of subtracting, I should add, but how do I do this in the same formula because each single measured value could be either positive or negative - ie, it's completely unknown until I measure it. The formula needs to be 'intelligent' enough to recognise if the measured value is positive or negative and then apply the correct subtraction or addition?.
Now, on the same flat surface, I place another object, measure the height = +6cm. Thus my positive height is +1cm because it is one value higher or, exceeding, the +5cm tolerance. I only need to see by how much the tolerance is exceeded. Hence the "if" argument.
Here is my problem, on the same surface, I place an object underneath the flat surface, I measure the height on the minus scale = -8cm, thus my sought after return value should be -3cm because it exceeds the -5cm tolerance by 3 units.
Again, help appreciated, it really seemed so simple to work out!.
