Sensitive material of MQ-7 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 when low temperature (heated by 1.5V). The sensor's conductivity is higher along with the gas concentration rising. When high temperature (heated by 5.0V), it cleans the other gases adsorbed under low temperature. Please use simple electro circuit, Convert change of conductivity to correspond output signal of gas concentration
Indication of the signal output
Dual signal output (analog output, and TTL level output)
TTL output signal is low. (When low output signal light, and can be connected directly to the microcontroller)
0 ~ 5V analog output voltage, the higher the concentration, the higher the voltage
Mainly used for CO collection detection in family, factory, underground operation.
Has a long life and reliable stability
Fast response and recovery characteristics
Technical parameters:
Size: 32X22X27mm
Main Chip: LM393, ZYMQ-7 gas sensor
Operating Voltage: DC 5V
Input Voltage: DC5V
Power: 150mA
DO Output: 0.1V/5V
AO Output: 0.1-0.3A