I AM GETTING A 0 TO -20 VDC SIGNAL FROM AN OSCILLATION SENSOR AND SENDING IT THROUGH AN INTRINSICALLY SAFE BARRIER. THE PROBLEM I HAVE IS I AM USING AN ANALOG I/O CARD THAT DETECTS +/-10VDC. I AM TRYING TO FIGURE OUT IF I CAN USE AN OP AMP TO CONVERT THE RANGE OF MY DC. MY SITUATION REQUIRES...