35-3010RK-05 Sample-Draw Detector • 5
Flow Block
The flow block is located in the lower right corner of the sample draw detector. All the
sensors are installed in the flow block. The flow block routes the sampled air to each
sensor.
EXHAUST Fitting
The EXHAUST fitting on the bottom of the housing allows the gas sample to exit the
sample draw detector. The EXHAUST fitting accepts 1/4 in. rigid tubing. See
“Installation” on page 8 for instructions to connect tubing to the EXHAUST fitting.
Detection System
Combustible Dummy Plug
The combustible sensor position in the flow block is occupied by a plastic dummy plug in
the 35-3010RK-05.
Oxygen Sensor
The oxygen sensor is installed in the lower right of the flow block. The oxygen sensor
includes the oxygen cell, connector, and sensor leads.
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. The signal from the sensor is sent to a
controller.
Connector
The cable that extends from the sensor terminates in a socket that plugs into a matching
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.
H
2
S Dummy Plug
The H
2
S sensor position in the flow block is occupied by a plastic dummy plug in the
35-3010RK-05.
CO Sensor
The CO sensor is installed in the upper left side of the flow block. It has 4 pins which mate
with sockets in the preamp circuit board.
Preamp Circuit Board
The preamp circuit is used to connect the CO and H
2
S sensors to the main circuit board
and to secure the sensors in the flow block. Two cables mate to the main circuit board: the
one on the left is for the CO sensor signal and the one of the right is for the H
2
S sensor
signal. Since the H
2
S sensor is replaced with a dummy plug in the 35-3010RK-05 the H
2
S
sensor signal cable carries no signal in this version of the 35-3010RK.
