I am using the A-198 with a frac setup, originally powering from a +/-12V supply but now trying to run it off of the +/-15V supply. It does work fine with just one exception. The pressure voltage now has a 3V offset. No finger on ribbon, panel pot fully clockwise, I get 3V. More if I press. How can I adjust this Is that what the trim pot is for

Thank you

Steve B