A composition of matter is provided having the general chemical formula K2P4, where x<0. IPDA having a cistrans isomer ratio in the range from 6337 to 6634 can be obtained in any desired cistrans isomer ratio, irrespective of temperature, by reacting IPDA with H2 and NH3 in the presence of a hydrogenation catalyst. Such information can be used by local circuitry in compensating the sensor while making ambient gas level determinations. Partial mapping values are selected from each compressed mapping sequence based on a bit index of the current input bit and summed or otherwise combined to get an output index.