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The DPM series flow meters integrate precision a differential pressure sensor
which accurately measures pressure drop across the special restriction flow
element (RFE). The geometry of the RFE is designed to ensure laminar flow in
each branch within the entire range of operation of the DPM instrument.
According to principles of fluid dynamics, the volumetric flow rates of a gas in the
laminar flow conduits are proportional to differential pressure across the
restriction flow element. In addition, precision absolute pressure and temperature
sensor readings are used to calculate mass flow rate using ideal gas laws.
The DPM flow meter supports multi-gas functionality which allows users on site to
select the desired measured gas using local Display/Joystick interface or digital
communication interface. See
Tables X - XVIII
which provide lists of supported
gases.
The DPM flow meter can display flow rate in 43 different mass flow or 15 different
volumetric flow engineering units. Flow meter parameters and functions can be
programmed locally via optional OLED/Joystick interface or remotely via the RS-
232/RS-485 interface or optional Modbus RTU interface. DPM flow meters
support various functions including two programmable flow totalizers; low, high or
range flow; temperature and pressure alarms; automatic zero adjustment
(activated via local or digital communication interface); programmable solid state
relay (SSR); programmable 0-5 Vdc, 0-10 Vdc or 4-20 mA analog outputs; user-
programmable pulse output (via SSR); and self-diagnostic alarms. Optional local
OLED readout with adjusta
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brightness level provides mass and volumetric
flow rate, total volume reading in currently selected engineering units, and
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FLOW MEDIUM:
Please note that DPM Mass Flow Meters are designed to work only with
cleangases,
never
any corrosive gas and
never
any liquid.
CALIBRATIONS:
Performed at standard conditions (14.7 psia [101.4 kPa] and 70 °F [21.1
°C]) unless otherwise requested or stated.
ENVIRONMENTAL (PER IEC 664):
Installation Level II; Pollution Degree II.
FLOW ACCURACY (INCLUDING LINEARITY):
±(0.5% RD + 0.2% FS) at calibration
temperature and pressure.
REPEATABILITY:
+0.15% of full scale.
FLOW TEMPERATURE COEFFICIENT:
0.05% of full scale/ °C or less.
FLOW PRESSURE COEFFICIENT:
0.01% of full scale/psi (6.895 kPa) or less.
FLOW RESPONSE TIME:
default 10 ms (user-adjusted).
