Principle Introduction:
Winsen Electronics is original manufacturer of MQ-7B Carbon Monoxide gas sensor, CO Gas sensor, with 80% market share in gas sensor field.
Sensitive material of MQ-7B gas sensor is SnO2, which with lower conductivity in clean air. It make detection by method of cycle high and low temperature, and detect CO at low temperature(heated by 1.5V).The sensor’s conductivity gets higher along with the CO gas concentration rising. At high temperature(heated by 5.0V),it cleans the other gases adsorbed at low temperature. Users can convert the change of conductivity to correspond output signal of gas concentration through a simple circuit.
Applications :
It is widely used in domestic CO gas leakage alarm, industrial CO gas alarm and portable CO gas detector.
Technical parameters :
Tips:For more parameter information, please refer to the latest manual provided by salesman.
| Model |
MQ-7B |
| Sensor Type |
Semiconductor |
| Standard Encapsulation |
Plastic cap |
| Target Gas |
carbon monoxide |
| Detection range |
10～500ppm CO |
| Standard Circuit Conditions |
Loop Voltage |
Vc |
≤10V DC |
| Heater Voltage |
VH |
5.0V±0.1V AC or DC（High tem.） 1.5V±0.1V AC or DC（Low tem.） |
| Heater Time |
TL |
60 S±1S（High tem.）， 90 S±1S（Low tem.） |
| Load Resistance |
RL |
Adjustable |
| Sensor character under standard test conditions |
Heater Resistance |
RH |
29Ω±3Ω（room tem.） |
| Heater consumption |
PH |
≤900mW |
| Sensitivity |
S |
Rs(in air)/Rs(in 150ppm CO)≥5 |
| Output Voltage |
Vs |
2.5V～4.3V (in 150ppm CO) |
| Concentration Slope |
α |
≤0.6(R300ppm/R50ppm CO) |
| Standard test conditions |
Tem. Humidity |
20℃±2℃；55%±5%RH |
| Standard test circuit |
Vc:5.0V±0.1V； VH（High tem.）： 5.0V±0.1V； VH （Low tem.）： 1.5V±0.1V |
| Preheat time |
Over 48 hours |
Datasheet Download
