Distortions of pressure measurements with a Bayard‐Alpert gauge in the range 10−4−10−3Torr were investigated, and changes in gauge sensitivity were found to be correlated with the observation of different electric charges on the glass envelope. A modified Bayard‐Alpert gauge was designed. The gauge incorporated a screen grid between the gauge elements and the glass envelope. The screen grid was connected to the gauge filament and was intended to reduce the impact energy of electrons on the glass surface and the interaction of electric charges on the envelope with charged particles in the gauge. Four modified gauges were built and tested, and the comparison of the gauges with a McLeod gauge showed that the ion‐collector current was a linear function of gas pressure over the range from 5 × 10−5to 7.2 × 10−4Torr. For further improvements, a beam type ionization gauge is proposed.