RKI Instruments 65-2507RK - Manual (Page 7)

65-2507RK Oxygen Transmitter • 3
Amplifier
The amplifier converts the electrical output from the oxygen detector to a 4 - 20 mA signal
that is proportional to the detection range and transmits the signal to the controller. The
amplifier includes the amplifier type selector, detector terminal strip, interconnect
terminal strip, span pot, zero pot, and test points (see Figure 1).
Amplifier Type Selector
The amplifier type selector is near the bottom left corner of the amplifier. It is below the
span pot and to the left of the detector terminal strip.
The amplifier included with the oxygen transmitter is designed for use with RKI’s oxygen
and toxic gas transmitters. The amplifier type selector determines for which transmitter
the amplifier is intended. For oxygen transmitters, a jumper block is installed over the
OXYGEN selector (see Figure 1).
Detector Terminal Strip
The detector terminal strip is the four-point terminal strip near the bottom of the
amplifier. Use the detector terminal strip to connect the oxygen detector to the amplifier.
NOTE: The oxygen detector is factory-wired to the amplifier. See the Installation section
of this manual for all wiring procedures related to the transmitter.
Interconnect Terminal Strip
The interconnect terminal strip is the four-point terminal strip near the top of the
amplifier. Use the interconnect terminal strip to connect the amplifier to the controller.
Span Pot
The span pot is on the left side of the amplifier. Of the three pots, the span pot is closest to
the bottom of the amplifier. Use the span pot to adjust the transmitter’s response output
during the start-up and calibration procedures.
Zero Pot
The zero pot is directly above the span pot. Use the zero pot to adjust the transmitter’s
oxygen-free output during the start-up and calibration procedure.
CAUTION: The amplifier includes an additional potentiometer above the zero potentiometer.
It is factory-set. Do not adjust it.
Test Points
The test points (labeled TP- and TP+) are directly to the left and right of the interconnect
terminal strip. The test points produce a 100 - 500 mV output that is proportional to the
transmitter’s 4 - 20 mA output. Use the test points and a voltmeter to measure the
transmitter’s output during the start-up and calibration procedures.