- R & M Supply Greenhouse Controller Specification Sheet

Page 7
PPM (Part-Per-Million) CO
2
CONTROL MODE
As mentioned previously, the CGC-1e can control CO
2
levels within the growing area with “Part-Per-Million” accuracy when
used in conjunction with the PPM-1c controller. Simply removing the jumper plug and connecting the PPM-1c into the
standard quick-disconnect on the bottom of the CGC-1e instantly gives you the ability to fully control all atmospheric
conditions which affect timed CO
2
systems.
*Note: The CO
2
Frequency timer acts as a CO
2
sample timer when using the PPM-1c controller. Because it may take a couple
of minutes from the time CO
2
is released for the PPM-1c to detect a higher CO
2
level, this timer will provide a delay for the
PPM controller to sense this increase in the CO
2
level before releasing more CO
2
. If you find the CO
2
level is “overshooting”
the CO
2
set-point, try increasing the CO
2
sample timer or decrease the CO
2
Inject timer. This will give the PPM-1c more time
to sense the rise in CO
2
resulting in reduced “overshoot”.
THE PPM-1c
The PPM-1c controller consists of an infrared detector capable of measuring atmospheric CO
2
levels from 0 to 5000 PPM. The
PPM-1c is powered by an 18 vdc to 24vac power supply. When it is connected, it will enter a “warm-up” mode. Once the
PPM-1c has completed the “warm-up”, it will begin to self calibrate. This may take an additional minute. During this time, the
digital readout may be fluctuating, this is normal. When the digital readout stabilizes, a level between 350 to 650 should be
displayed. Be careful however, simply breathing on the PPM-1c controller will greatly increase the CO
2
level in the air
resulting in a higher reading.
IMPORTANT!!! Do not start a CO
2
cycle until the PPM-1c has completed the “warm-up” and the display has stabilized.
Once the PPM-1c has been connected, it remains powered as long as it is plugged in. The controller will continuously display
the exact CO
2
PPM level in part per million.
The PPM-1c is a portable device and comes with a 5-foot cable so that spot checks can be made.
A simple procedure allows the user to check and reset calibration… otherwise; the PPM-1c requires no adjustment or service.
Warning: Be careful not to expose the PPM-1c to water, as it is not water-resistant!