ZG09 CO
2
Module
http://www.ZyAura.com
REV. 082018
7. PWM Output
Adjustable CO
2
measurement range PWM VCC (3.0~3.3V) level at 1 kHz output 0~10,000ppm. Schematic is as Figure 3.
AL1=0~10,000ppm, AL2=0~10,000ppm. The AL1<AL2 setting is for HVAC. AL1>AL2 setting is for agriculture, If the gas
concentration for agriculture is 0-10,000ppm, then the AL1=0ppm, AL2=10,000ppm.
Figure 3
Application
AL1 0~10,000ppm
AL2 0~10,000ppm
Remark
CO
2
monitoring
0ppm (0V)
10,000ppm (VCC)
HVAC
800ppm default (<800ppm=0V)
1200ppm default (>1200ppm=VCC)
Note 1
Agriculture
Adjustable
Adjustable
Note 2
Note 1: For HVAC, the ventilation will be activated when the CO
2
concentration is higher than AL2 1200ppm (adjustable). The
ventilation will be inactivated when the CO
2
lower than 800ppm(adjustable).
Note 2: For planting, the alarm setting is AL1>AL2. The CO
2
generator will be activated when the CO
2
concentration is lower than
AL2 400ppm (adjustable). The CO
2
generator will be inactivated when the CO
2
concentration is higher than AL2 1200ppm
(adjustable). The difference between AL1 and AL2 has to be 100ppm at least.
8. DAV Output
DAV output can be controlled by user. For high precise CO
2
monitoring is not recommended. Output 0~1V = default 800~1,200ppm
(210 steps). The range can be controlled by AL1 and AL2. Users can use comparator to control the relay. AL2>AL1 is for HVAC.
AL1>AL2 is for agriculture. When AL1 is 800ppm and the CO
2
reading is also 800ppm, DAV output is 0V. AL1=0 and
AL2=10,000ppm is for full range output.
9. Reliability
9.1 Long term stability
16 samples were on long-term test (25°C, 70% RH, 500 hours) and the average results are shown in Figure 4.
The Y axis is the CO
2
concentration and the X axis is the time.
Figure 4