Sentinel CHHC-1 Instruction Manual - page 6
Understanding Interlocks
Understanding how the unit works is important if you are going
to get the most out of the unit.
Interlocks are used to select if certain functions will be interlocked
“linked” together or operate independently. For example, if you want
the CO2 device to be disabled while the ventilation - fan is operating,
you can select the
CO2 / Temp interlock
to be activated by setting the
interlock to connect mode. See below for details.
Interlock CO2 / Temp
* Using ventilation fans for cooling.
If you are using ventilation fans to keep the growing area cool, warm
and humid air inside the growing area is being replaced by dry and
cooler outside air from outside the area. It is advisable to NOT
operate the CO2 device when a ventilation fan is in the process of
exchanging air. So is this example you would want to select to
connect the
Interlock CO2 & Temp
so that the CO2 is turned OFF
when the cooling fan is activated. This will reduce the amount of CO2
being used and reduce waste.
Using air conditioning for cooling.
If you are using a recycling air conditioner to keep the growing area
cool, the air inside the growing area is NOT being exchanged with
outside air. There is no problem operating the CO2 device and the
cooling device AT THE SAME TIME. So is this example you would
want to select to split the
Interlock CO2 & Temp
so that the CO2 is
controlled independently of the cooling device. If the area gets too
warm, the cooling device will operate, if the CO2 is too low, the CO2
device will operate completely independent of each other.
NOTE: There are exceptions to this rule. If you are operating compressed
CO2, it is important to disable the CO2 while the ventilation fan is
operating, because of the high-cost of CO2. However if you are operating
an economical CO2 generator, you may choose to allow both the ventila-
tion fan and the CO2 generator to run at the same time. (see below)
NOTE: If you are using a CO2 generator, you may want to choose to
disable the CO2 generator while the air conditioner is operating to
reduce the amount of heat it needs to remove. (see above)
Calibrating the CHHC-1
CO2 Calibrate
Even though the CHHC-1 has been designed
for many years of trouble-free operation, occasional the need
arises to re-calibrate the CO2 sensor. Calibrating the unit will
restore the sensor’s ability to accurately measure the CO2 levels.
The CO2 sensor has a lifetime of over 10 years. However, over the life
of the sensor, dust and other contaminants can accumulate on the inner
optical surfaces of the sensor cell itself. To adjust for the contamination,
the calibration feature is provided. If the unit appears to not be
measuring the CO2 levels correctly or if the unit has been dropped or
jarred severely, you should recalibrate the unit.
1) Locate an area outdoors away from people, animals and high traffic areas.
The unit must be shaded and NOT placed in direct sunlight.
2) Plug in the unit in and allow the unit to warm up for approximately 30
minutes. Note: Waiting longer (1+ hours) provides more accurate calibration.
3) Try not to exhale or breath on the unit while activating the calibration
function. Once activated, leave the unit alone for at least 10 minutes.
4) To activate the automatic calibration sequence, press the CO2 Calibrate
button. will display the “new” ambient CO2 level
_380_PP
. If the unit will be
calibrated in an area of high vehicular traffic, or near people, a slightly higher
calibration point should be selected.
5) The calibration level can be changed by using the UP and Down buttons. If
you live in a highly populated city, you may increase the calibration level to 400-
475 PPM.
6) Pressing
Enter / Reset will start the calibration process. The display will
read
Co2_CAL
and a small green LED will be flashing.
LEAVE THE UNIT
ALONE! The process takes about 2-6 minutes. When complete, the display re-
turns to normal operation.
7) The CO2 sensor calibration can be repeated as often as necessary
NOTE: Recalibration of the CO2 sensor must be completed away from
all animals and people OUTDOORS! Follow the procedure exactly.
NOTE: Annual calibration is HIGHLY recommended.