10 • 35-3001A-01-XX1 Sample-Draw Detector Operator’s Manual
Pump Connector
The pump connector is the two-point connector below the oxygen terminal strip in the upper
right corner of the main circuit board. Use the pump connector to connect the pump to the
main circuit board.
NOTE:
The pump is factory-wired to the main circuit board. See “Installation” on page 12
for all wiring procedures related to the sample-draw detector.
Flowmeter Circuit Board Connector
The flowmeter circuit board connector is a six-position connector in the upper left corner of
the main circuit board. Use the flowmeter circuit board connector to connect the flowmeter
circuit board to the main circuit board.
NOTE:
The flowmeter circuit board is factory wired to the main circuit board. See
“Installation” on page 12 for all wiring procedures related to the sample-draw
detector.
Flowmeter Circuit Board
The flowmeter circuit board is mounted to the left side of the main circuit board using
standoffs. It includes the flowmeter, sensor flow control valve, status LEDs, pressure switch,
and pump reset switch.
Flowmeter
The flowmeter is mounted to the right side of the flowmeter circuit board. You can see it
through the window in the door. A ball in the flowmeter column indicates the flow rate to the
sensor. The flowmeter measures the flow in the range 0.2 to 2.0 SCFH (Standard Cubic Feet
per Hour). The optimum flow rate is 1.0 SCFH.
Sensor Flow Control Valve
The sensor flow control valve is mounted to the flowmeter circuit board above the flowmeter.
The sensor flow control valve adjusts the flow rate to the detector. Turn the valve’s knob
counterclockwise to increase the flow and clockwise to decrease the flow.
Status LEDs
Two status LEDs are above the flowmeter. They are also visible through the window in the
housing door. The green Pilot LED is on when the sample-draw detector is receiving power
from the controller. The red Fail LED is on when the sample flow rate is below the low flow
level.
Pressure Switch
The pressure switch is mounted to the back of the flowmeter circuit board. The pressure
switch monitors the flow rate of the incoming gas sample.
