RKI Instruments 35-3000RK-OXY - Manual (Page 7)

35-3000RK-OXY Sample-Draw Oxygen Detector • 7
Status lights
Two status lights are above the flowmeter. They are also visible through the window in
the housing door.
Pilot light
The green Pilot light is on when the sample-draw detector is receiving power from the
Controller.
Fail light
The red fail light is on when the sample flow rate is below the low flow level
NOTE: The factory set low flow level is 0.6 SCFH (±0.2). See “Adjusting the Low Flow
Setting” on page 16 to adjust this setting.
Pressure switch
The pressure switch is mounted to the opposite side of the main circuit board. The
pressure switch monitors the flow rate of the incoming gas sample.
If the flow rate falls below the preset low flow level, the pressure switch causes the fail
relay to interrupt the signal from the sensor. The interrupted sensor signal causes a fail
condition at the controller. The low flow level is factory-set at 0.6 SCFH (±0.2 SCFH).
Exhaust fitting
The exhaust fitting on the right side of the housing allows the gas sample to exit the
sample-draw detector. The exhaust fitting accepts 1/4 in. rigid tubing. See the Installation
section on page 9 to connect tubing to the exhaust fitting.
Detection System
The detection system consists of the oxygen sensor and the main circuit board.
Oxygen sensor
The oxygen sensor is installed in a cavity block. The cavity block is mounted to the
aluminum
subpanel near the bottom of the sample-draw detector. The oxygen sensor
includes the oxygen cell, connector, and sensor leads.
NOTE: The cavity block includes a cavity for a combustible gas sensor. This version of
the sample-draw detector does not include the combustible gas sensor.
Oxygen cell
The oxygen cell is protected within the sensor assembly. Through a series of chemical and
electronic reactions, the cell produces a millivolt output that is proportional to the
detection range of the sample-draw detector.
Connector
The cable that extends from the sensor terminates in a 7-position socket that connects to a
mating 7-pin male connector. The socket and connector allow you to replace the sensor
without disconnecting the wiring. The sensor leads are soldered to the male connector.
Sensor leads
Two color-coded leads extend from the connector. The leads allow you to connect the
oxygen sensor to the main circuit board.