> I read your prose correctly, you are using a non-inverting
> configuration of the op amp.  The trouble with this is that the gain
> will vary depending on the setting of the offset pot, and the output
> will be nonlinear.  This may not be a problem, but I think you would be
> a lot better off using an inverting configuration.
You are correct and my post was in error the first opamp is inverting.
prose?  Tony M.