Shown here is a chart summarizing the features of the three handheld digital manometers. The updated microcomputer used in PG-100N and PG-100B series provides additional functions to the digital manometer. Zero-point adjustment can be achieved with a single touch of a button. Pressing down on the “Zero” button for 3 seconds will automatically calibrate the zero-point to atmospheric pressure. Pressure units can be changed in selected models. The PG-100N and PG-100B series run on commercially available AAA batteries. Battery life is 1,000 hrs. minimum on alkaline batteries. The PG-100B is capable of measuring both gas and liquid.