Check the listing for details. MQ-7 MQ7 Carbon Monoxide Gas Sensor Detection Alarm Sensor Module for Arduino. Condition: New. Listed at 4.67 USD. MQ-7 MQ7 Carbon Monoxide Gas Sensor Detection Alarm Sensor Module for Arduino - Descriptions: MQ-7 gas sensor is sensitive material used in clean air, low conductivity tin dioxide (SnO2). Detection method using low temperature cycling (1.5V heating) detect carbon monoxide, airborne sensor conductivity increases with the increase of the concentration of carbon monoxide gas, high temperature (5.0V heating) cleaning stray gas. Features:Testing gas: Carbon Monoxide Detection of concentration: 10-1000ppmCO Loop voltage: 10V DC Heater voltage: 5V±0.2V ACorDC(high), 1.5V±0.1V ACorDC(low) Load resistance: adjustable Heating resistor: 31±3(indoor temperature) Heating dissipation: 350mW Sensitive part surface resistance: 2K-20K Sensitivity: Rs(in air)/Rs(100ppmCO)5 Concentration gradient: 0.6 Temperature, humidity: 20±2, 65%±5%RH Standard test circuit: Vc: 5v ±0.1v, Vh(high): 5v ±0.1v, Vh(low): 1.5v ±0.1v - Package Contains: 1pc x MQ-7 Carbon Monoxide Gas Sensor Module (see the picture) - Pictures: