10 • 35-3010A-12 Sample-Draw Detector
intended. For oxygen transmitters, a jumper block is installed over the OXY selector.
Detector Terminal Strip
The detector terminal strip is the four-point terminal strip near the bottom edge of the transmitter.
It is factory wired to the transmitter.
Interconnect Terminal Strip
The interconnect terminal strip is the four-point terminal strip near the top edge of the transmitter.
It is factory wired to the main circuit board.
Span/Zero Pots
The span and zero pots are located on the left side 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.
Test Points
The test points are located on the top of the transmitter on either side of the transmitter intercon-
nect terminal strip. They 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.
Main Circuit Board
Figure 4: Main Circuit Board
The main circuit board includes the interconnect terminal strip, sensor/transmitter terminal strip,
amp 1 circuit, amp 2 circuit, pump terminal strip, relay, and reset switch (see Figure 4).
Test Point CAL - 2
Amp 1
(CO)
Zero
Span
Zero
Sensor/Transmitter
Terminal Strip
Interconnect T erm inal
Strip
Amp 2
(H2S)
Span
Test Point CAL + 1
Test Point CAL - 1
AC T erm inal Strip Not Used
Test Point CAL + 2
Pump Terminal Stip
Low Flow A djust
Flow Adjust Pot
Pressure Switch
Relay
Reset Switch
Fail LED
Pilot LED
Flowmeter