The PG7601 covers absolute and gauge pressures with gas including pressures near and under atmospheric pressure. The unit includes support for establishing and measuring a vacuum reference for defining absolute pressures relative to an evacuated bell jar. Includes bell jar and integrated vacuum gauge. Also supports “differential mode” operation to cover positive and negative differential pressures near zero and at different static pressures. Gas pressure range of 1 to 1000 psi (7 kPa to 7MPa).