Another scaling question ;) ???

3 transducers in the field!! 2 work and scale just fine the mechanical linkage is shaped like a V transducer on one side, pivot at the point of the V, and other side doing the movement. Within 1/2" which is fine for this crude process and their some slop in the linkage, so it does what we need it to do.

Well, the other is shaped more like a scissor life slanted 30 degrees. The High and Low is dead on, but anyplace in the middle is off by up to 20%.

I think it's do to the mechanical piece not being linear in the field. Too many rotating pieces too many fulcrum points. Others think this used to work.

IMO, if the range was say 5ma low and 15ma high scaled to 50 and 150 for ease of understanding.

If the card saw 10ma from the transducer you would read 100, correct? That is what we see the ma signal corresponds dead on with the panelview, but the field device does not.

Here is my crude attempt to explain how it is mount and it does look something like a scissor life in the field. Thoughts? It' almost like it needs to be scaled non linear see attached pics.

The first is sort of what the field device is like just imagine it at 30 degrees and the other is my Paint interpretation of what a conventional scaling looks like in comparison to how this seems like it would need to be scaled in (Green) to have the correct values on the Panelview. Or thoughts on a transducer going bad?

Im not sure exactly what you are describing but if you are trying to correlate acturator stroke to height of platform, that is definitely not linear. look at your graph. A small Y movement causes a large X movement at bottom of graph but the same Y movement at top of graph gives a small X.
In the scissor lift example, a small extension of the cylinder causes a big movement of the platform at the bottom.
I believe it is actually a sine wave function. you could use some math to linearize it.

I would try using the square root of the number to linear the input.

http://www.sensorsone.com/linear-measurement-to-square-root-extraction-4-20ma-converter/

Regards,
Garry
http://www.accautomation.ca

What would you like to measure? the pressure in the cylinder, or the horizontal force, or the vertical one.
They are far from linear.
It all works with sinus and cosinus angles.
or do it with maths, or do it with an array.
If the platform is low, the force in the cylinder is low, and the horizontal force is high, at the top the platform is slow but the force is also low.