Abstract: An improved SCUBA diving gauge. A pictograph display is provided which has a shape which conveys the type of information being displayed. The pictograph has the shape of a SCUBA tank for a tank pressure display and the shape of a person for a display of nitrogen absorbed. Pressure transducers coupled to the SCUBA tank and the external water provided the pressure readings required to produce the respective displays. The differential signal from the transducer is supplied to a processor through an auto-zeroing circuit. The auto-zeroing circuit uses a capacitor initially coupled to an amplifier reference input and single ended output to store an offset voltage. During a measurement, the capacitor is disconnected from the amplifier output and has its other lead coupled to a full scale value of the differential input to produce an output signal which is a ratio.