35-3010RK-07 Sample-Draw Detector • 5
Flow Blocks
Both flow blocks are located in the lower right corner of the sample-draw detector. The
oxygen and H
2
S sensors are installed in the larger flow block. The smaller flow block
houses the IR CH
4
sensor. The flow blocks route 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
The detection system consists of the IR CH
4
, oxygen and H
2
S sensors, preamp circuit
board, and the main circuit board.
IR CH
4
Sensor
The infrared CH
4
sensor is installed in the smaller flow block in the lower right corner. A
small circuit board with a cable mates to it and retains it in the block. The cable is wired to
the main PCB.
Oxygen Sensor
The oxygen sensor is installed in the lower right of the larger flow block. It consists of a
cylindrical body which houses the detection elements and a cable which terminates in a
round 7-pin male connector. The sensor connector mates to a 7-position socket that is
wired to the main PCB.
CO Dummy Plug
The CO sensor position in the flow block is occupied by a plastic dummy plug in the
35-3010RK-07.
Hydrogen Sulfide Gas Sensor
The hydrogen sulfide gas sensor is installed in the upper right side of the flow block. It
has 4 pins which mate with sockets on 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 CO sensor is replaced with a dummy plug in the 35-3010RK-07 the CO
sensor signal cable carries no signal in this version of the 35-3010RK.
