16 – LOW PRESSURE EXTERNAL
PLUMBING
This option applies to a PCS 400 with a full scale
range of 3 psig or lower. These low ranges require
the installation of special hardware on the pneu-
matic ports as illustrated in figures 8.13 and 8.14.
This additional hardware is supplied by Mensor
and is shipped with the instrument.
The item shown attached to the REFERENCE port
is a pressure snubber made up of a capped T-fitting
with an installed filter. Its purpose is to dampen
out the ambient pressure changes caused by such
things as doors being opened or closed, or the
cycling of blowers on heating/air conditioning sys-
tems. These minor pressure variations are signifi-
cant when trying to accurately measure and control
very low pressures.
If a device under test includes a reference port,
connect that port to the capped end of the filter
fitting on the PCS 400 REFERENCE port.
A Conoflow™ pressure regulator is shown attached
to the SUPPLY port. Apply 20 to 30 psig source
pressure to the end of this device that has “IN”
molded into the casting. The opposite end connects
directly to the PCS 400’s SUPPLY port.
Connect a vacuum pump to the EXHAUST port,
and connect the device under test (DUT) to the
MEASURE/CONTROL port.
With the test setup connected in the above manner
very low pressure testing can proceed with a mini-
mum of interference from outside influences. For
additional assistance with specific questions or
problems contact Mensor.
REFERENCE
Vac
Pump
PCS 400 Pneumatic Connections
DUT
20 to 30 psig in
Conoflow Flow Controller
Filter
MEASURE/
CONTROL
EXHAUST SUPPLY
Figure 8.13 - Pneumatic Connections for Low Pressure
PCS 400 OPTIONS
www.mensor.com 8-19