Residual pressure detectors are categorized into differential pressure residual pressure detectors and dynamic pressure residual pressure detectors, based on their pressure measurement principles. Differential pressure residual pressure detectors require the detection of pressure differences between two spaces, hence, when installing the equipment, in addition to installing a residual pressure detector in the pressurized/high-pressure area (elevator shaft or stairwell), a gas tube must also be connected to the atmospheric/low-pressure area (corridor). This gas tube is used for detecting the pressure in the atmospheric/low-pressure area.

The counterpart to the differential pressure residual pressure detector is the dynamic pressure residual pressure detector, which does not require a gas line connection. It simply needs to be installed in the pressurized area/high-pressure area, such as the antechamber or stairwell.

Installing differential pressure residual pressure detectors is more convenient than installing static pressure detectors, as it eliminates the need for air pipes. This means no drilling is required between the lobby and corridors, or between stairwells and corridors. Consequently, construction is easier and the installation location is more flexible.

Therefore, it is recommended to opt for dynamic pressure differential pressure detectors when choosing exhaust pressure detectors.