Thermo Scientific 5028i Instruction Manual page 227

Flow Sensor System
Pressure Sensor Assembly
Detector Amplifier
Digital Output Board
Thermo Fisher Scientific
24 V and 220 VAC power supply inputs
l
Fan and solenoid outputs
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220 VAC output and thermistor input from the sample heater
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Flow and pressure sensor inputs
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Proportional valve output
l
Optical pickup input
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Pre-amp board
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Ambient temperature/RTD and RH
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Flow RTDs
l
The flow sensor system consists of a subsonic orifice inside the primary
measurement head, a differential pressure and vacuum sensors, and
a flow temperature RTD. The flow system output is produced by
measuring the pressure difference across a precision orifice. This unit is
used for measuring the flow of sample gas in the measurement system.
The pressure sensor assembly consists of a board containing five pressure
transducers with tube connections. The pressure transducer output is
produced by measuring the pressure difference between the sample gas
pressure and ambient air pressure.
The detector amplifier assembly amplifies the signal from the
proportional detector that receives beta particle emissions from the
Assembly
C-14 source through the sample and filter tape. The output of the
detector amplifier is fed to the measurement interface board. A coaxial
cable from the detector amplifier supplies power and grounding to the
detector.
The digital output board connects to the motherboard and provides
solenoid driver outputs and relay contact outputs to a connector located
on the rear panel of the instrument. Ten relay contacts, normally open
(with power off), are provided, which are electrically isolated from each
other. Eight solenoid driver outputs (open collector) are provided along
with a corresponding +24 VDC supply pin on the connector.
System Description
Electronics
Model 5028i Instruction Manual 8-7