TSI Instruments 3022A - Schematic of the DMPS;CPC in the Underpressure Mode

10-4 Model 3022A Condensation Particle Counter
need to plug the makeup air flow to force more air to be drawn from
the reduced-pressure inlet (see “Inlet Pressure” in Chapter 4).
Figure 10-2
Schematic of the DMPS/CPC in the Underpressure Mode