mensor PCS 400, Руководство по эксплуатации

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INSTALLATION
MOUNTING
The instrument can be set up on a table-top or it
can be rack-mounted. For rack-mount installation,
see the instructions in Section 8,
Options .
The special sensor used in the PCS 400 is relatively
insensitive to tilt and vibration. However to further
assure stability and accuracy, excessive motor or
machinery vibration of the mounting surface
should be avoided.
PRESSURE CONNECTIONS
NOTE:
When making up connections to
the o-ring adapter use a back-up wrench
to prevent over-stressing the threads in
the manifold block.
The pressure ports on the rear manifold block are
female 7/16 - 20 SAE/MS straight threads per
MS16142 and SAE J514 table 14. They require a
tube fitting boss seal with an o-ring per MS33656.
Mensor provides female 1/8 NPT adapter fittings
with the instrument. The pressure connection can
be made to these adapters with the proper mating
hardware. We recommend the use of either Loctite
Hydraulic Sealant or fresh teflon tape on the
threads of the male pipe fitting. Do not use sealants
on fittings sealed with an o-ring. The integrity of the
seal is particularly important since even micro-
scopic leaks can cause errors in measurements.
Figure 9.2 is a pneumatic schematic of the internal
plumbing (see figures 9.3 through 9.6 in the
Appen-
dix for additional pneumatic schematics showing
optional configurations).
Table 9.5 in the Appendix shows the status of
solenoid valves L1 through L6 during different
operating conditions. Requirements for connecting
to the various ports on the
PCS 400
manifold are
given below.
SUPPLY Pressure Port
Connect a pressure source to the SUPPLY port of
the
PCS 400
. This pressure will be used to derive
the CONTROL pressure output at the MEAS-
URE/CONTROL port. The supply pressure must be
greater than the highest control pressure that will
be commanded which is usually the full scale (FS)
range of the instrument.
EXHAUST Pressure Port
The EXHAUST pressure port is either left open to
atmosphere or connected to a vacuum pump in
order to control at pressures below atmospheric
pressure. A vacuum pump will also improve con-
trol for positive pressures below 0.25 psig.
MEASURE/CONTROL Pressure Port
The MEASURE/CONTROL port is a bi-directional
port. It can receive an unknown pressure to be
measured, or upon command it can output a con-
trolled pressure to external devices. In the MEAS-
URE mode, solenoid valve L5 is closed (see table
9.5, Solenoid Valve Truth Table, in the
Appendix ).
This isolates the regulator from the port but leaves
the measure path open to the transducer(s). In
CONTROL mode, L5 is opened to allow the regu-
lated pressure output to reach the same port.
For optimum CONTROL performance the external
system connected to this port should consist of a
total volume between 0.01 and 0.5 liters. External
volumes less than 0.01 liter will decrease control
stability, and volumes greater than 0.5 liter will
increase overshoot and control times.
REFERENCE Pressure Port
If an optional Barometric Reference Transducer
(BRT) is included in the
PCS 400
, the REFERENCE
port might be internally connected to its pressure
port. If there is no BRT then the REFERENCE port
is either connected to the reference port(s) of the
gauge pressure transducer(s), or internally plugged
on absolute units. Refer to the
Appendix section of
the manual for the appropriate pneumatic sche-
matic diagram that applies to your instument.
CAUTION: HIGH NOISE LEVELS.
As pressure decreases compressed gas will
escape out the EXHAUST port. For ranges
above 600 psi high noise levels may result
during such pressure releases. To overcome
objectionable exhaust noise either install a
muffler or route the port to a remote
location.
PCS 400
INSTALLATION
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