10 • 35-3010A-11 Sample-Draw Detector
IR CO
2
Transmitter
The IR CO
2
transmitter is mounted above the main circuit board. It consists of the span
pot, zero pot, one internally wired terminal strip, and the test points.
Figure 3: IR CO
2
Transmitter
Span/Zero Pots
The span and zero pots are located at the bottom edge of the transmitter and are used for
calibration. Use the span pot to make adjustments to gas response readings and the zero
pot to make adjustments to the zero reading.
Transmitter Interconnect Terminal Strip
The transmitter interconnect terminal strip is the seven-point terminal strip near the right
edge of the transmitter. The transmitter is factory wired to the sensor and main circuit
board.
Test Points
The test points are located on the left side of the transmitter and are labeled TP+ and TP-.
A 100 mV - 500 mV output is available at these test points for use during calibration.
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 35-3010A-11 the CO
sensor signal cable carries no signal in this version of the 35-3010RK.
Zero Pot
Interconnect
Terminal Strip
Test Point TP-
Test Point TP+
Span Pot
