RKI Instruments 35-3000RKA-H2S User Manual
Page 5
Sample-Draw Hydrogen Sulfide Gas Detection • 5
Hydrogen Sulfide Transmitter
The hydrogen sulfide transmitter is mounted to the left of the hydrogen sensor. It consists
of the span pot, zero pot, two internally wired terminal strips, and the test points.
Span/zero pots
The span and zero pots are located at the left edge of the transmitter and are used for cali-
bration. Use the span pot to make adjustments to gas response readings and the zero pot
to make adjustments to the zero reading
Termainal Strips
There are two terminal strips which are used for internal factory wiring.
Test points
The test points are located at the top of the transmitter and are labeled
TP+
and
TP-
. A
100 mV - 500 mV output is available at these testpoints for use during calibration.
Main Circuit Board
The main circuit board includes the interconnect terminal strip, transmitter terminal strip,
pump terminal strip, and relay (see Figure 1).
NOTE:
The flowmeter and status lights are mounted to the main circuit board but are
considered part of the flow system.
Interconnect terminal strip
The interconnect terminal strip is the nine-point terminal strip near the bottom edge of the
main circuit board. Use the interconnect terminal strip to connect the sample-draw
detector to power and an external device.
Transmitter terminal strip
The transmitter terminal strip is the nine-point terminal strip near the right edge of the
circuit board. Use the transmitter terminal strip to connect the transmitter to the main
circuit board.
NOTE:
The transmitter is factory-wired to the circuit board. See the “Installation” section
on page 6 for all wiring procedures related to the sample-draw detector.
Pump terminal strip
The pump terminal strip is the four-point terminal strip near the top edge of the circuit
board. Use the pump terminal strip to connect the pump and pressure switch to the main
circuit board.
NOTE:
The pump and pressure switch are factory-wired to the circuit board. See the
“Installation” on page 6 for all wiring procedures related to the sample-draw
detector.
Relay
The relay is to the left of the detector terminal strip. The relay is double pole, double-
throw (DPDT) and is rated for 2 amps at 25 VDC (resistive). If the pressure switch senses a
low flow condition, the relay interrupts the signal from the sensor. The interrupted sensor
signal causes a fail condition at the Pioneer.