18 • 65-2397RK CO
2
Transmitter
NOTE:
When a transmitter is first powered up with a new amplifier, the initial output may be either
high or below zero depending on the setting of the zero pot. Be sure to make arrangements so
that this does not cause unwanted alarms.
10. Turn on power to the controller.
11. Turn on the controller and place it into normal operation.
NOTE:
When first powered up, the transmitter will enter about a one minute period when the 4-20
mA output is stabilizing and may be above the controller alarm points or well below zero
momentarily. RKI controllers have a one minute warmup period when the controller does not
display any gas reading or give any alarm indication. The CO
2
transmitter’s 4-20 mA signal
should be stable by the time the controller’s warmup period is over.
12. Allow the transmitter to warm-up for 5 minutes.
13. Calibrate the transmitter as described in “Calibration” on page 19 of this manual.
Calibration Frequency
Although there is no particular calibration frequency that is correct for all applications, a calibration
frequency of every 6 months is adequate for most infrared CO
2
transmitter applications. Unless
experience in a particular application dictates otherwise, RKI Instruments, Inc. recommends a
calibration frequency of every 6 months.
If an application is not very demanding, for example detection in a clean, temperature controlled
environment where calibration adjustments are minimal at calibration, then a calibration frequency of
every 9 to 12 months is adequate.
If an application is very demanding, for example if the environment is not well controlled, then more
frequent calibration than every 6 months may be necessary.
Table 5:Reconnecting the CO
2
Detector to the Amplifier
Amplifier Detector
Terminal Strip
Detector Lead
DETECTOR “R”
RED
DETECTOR “W”
WHT
DETECTOR “G”
GREEN
DETECTOR “B”
BLK
