MQ-7
FEATURES
* High sensitivity to carbon monoxide
* Stable and long life
APPLICATION
They are used in gas detecting equipment for carbon monoxide(CO) in family and
industry or car.
SPECIFICATIONS
A. Standard work condition
Symbol Parameter name Technical condition Remark
Vc circuit voltage 5V±0.1 Ac or Dc
VH (H) Heating voltage (high) 5V±0.1 Ac or Dc
VH (L) Heating voltage (low) 1.4V±0.1 Ac or Dc
RL Load resistance Can adjust
RH Heating resistance 33Ω±5% Room temperature
TH (H) Heating time (high) 60±1 seconds
TH (L) Heating time (low) 90±1 seconds
PH Heating consumption About 350mW
b. Environment conditions
Symbol Parameters Technical conditions Remark
Tao Using temperature -20℃-50℃
Tas Storage temperature -20℃-50℃ Advice using scope
RH Relative humidity Less than 95%RH
O2 Oxygen concentration 21%(stand condition)
the oxygen concentration can
affect the sensitivity
characteristic
Minimum value is over 2%
c. Sensitivity characteristic
symbol Parameters Technical parameters Remark
Rs Surface resistance
Of sensitive body
2-20k
In 100ppm
Carbon Monoxide
а(300/100ppm) Concentration slope rate Less than 0.5 Rs (300ppm)/Rs(100ppm)
Standard working Temperature -20℃±2℃ relative humidity 65%±5% RL:10KΩ±5%
condition
Vc:5V±0.1V VH:5V±0.1V VH:1.4V±0.1V
Preheat time No less than 48 hours Detecting range:
20ppm-2000ppm carbon monoxide