Intek RheoVac SENTRY - Manual (Page 15)

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SECTION 3 — OPERATION
3.1 GENERAL INFORMATION
The RheoVac probe outputs are compensated and linearized for a wide range of flowing media
temperatures, pressures, and water vapor contents. However, abrupt changes in these parameters can
cause the instrument to temporarily read the flow rate improperly, which could lead to transient spikes
in the flow indication. In particular, if liquid (water) hits the probe tips, there will be high flow
indications until all the water vaporizes. This is a rare occurrence that should not happen if the probe
is properly installed per instructions in SECTION 2 — INSTALLATION.
3.2 OUTPUT PARAMETERS
The RheoVac SENTRY System measures and calculates ten output parameters. These are accessible on
the touch screen display, through ethernet, or modem connection. These output parameters are:
Table I - Output Parameters
PROCESS VARIABLE PROCESS VARIABLE DEFINITION
ACTUAL VOLUME FLOW
[ACFM]
The actua l volumetric flow rate of gas es leaving the cond enser. It is a measur e of
pump capacity. Decreased capacity means pump degradation.
TOTAL MASS FLOW
[lbs/hr]
The total mass flow rate of the flowing gas. Note: this value is not a measure of air in-
leak. It is a meas ure of s team j et air e jector capa city.
WATER VAPOR MASS FLOW
[lbs/hr]
The water vapor component of the flowing gas being removed from the condenser.
RheoVac PRESSURE
[" Hg]
Absolute pressure at the RheoVac probe head. Should be equal to or less than turbine
back pressure.
WATER VAPOR SPECIFIC
VOLUME [cu. ft/lb]
The inverse density of the water vapor present in the line.
WATE R to AIR MA SS RATIO Ratio of water vapor flow rate to dry air flow rate. D efines “vacuum quality.”
RELATIVE SATURATION
[%]
The percent concentration of water vapor in the extraction line relative to saturation.
PARTIAL PRESSURE,
WATE R ["Hg]
The partial pressure of water vapor in the vacuum line.
AIR IN-LEAK
[SCFM]
Actual measure of air volume flow rate passing the RheoVac sensor head, normalized to
standard conditions
(70°F, 29.9" HgA).
RheoVac TEMPERATURE
[°F]
Temperature of the flow media at the RheoVac probe head.
3.3 RheoVac SENTRY PROBES
In the RheoVac SENTRY System, multiple probes are installed in strategic locations of the condenser
system. Sometimes the locations will be labeled on the screen by Intek during manufacture or by the
customer after installation. As the SENTRY CPU only recognizes the probe’s identity (via its unique
serial number), and does not recognize physical locations, it is important that the assigned location for