The CPS-40M Contamination Prevention System (40 MPa / 6000 psi) is an accessory for 6270A, 8270A or 2271A pressure controllers to protect the pressure controller from contamination in the test device.
See the linked file at the end of this article for a detailed description of how the CPS-40M works with various setpoints and conditions.
Also see the CPS-40M/100M instruction sheet here,
Coalescing filter spec: 0.01 micron filtering efficiency of 95% (however, only the gas that is vented to atmosphere flows through this filter). See attached document for more detailed.