Keywish Basic Gas Sensor MQ-2 MQ-3 MQ-4 MQ-5 MQ-6 MQ-7 MQ-8 MQ-9 MQ-135 Sensor kit set for Arduino Starter Kit gas detection;

Component list:
1 x Project Box
1 x User Manual
1 x MQ-2
1 x MQ-3
1 x MQ-4
1 x MQ-5
1 x MQ-6
1 x MQ-7
1 x MQ-8
1 x MQ-9
1 x MQ-135
1 x 400 Holes Breadboard
20 x Dupont wire (Female to Male)
2 x 24cm Jumper Wire (Male to Male)
2 x 20cm Jumper Wire (Male to Male)
4 x 16cm Jumper Wire (Male to Male)
22 x Jumper Wire 25cm (Male to Male)

Features:Gas Sensor Detector Module can be used in the gas leakage monitoring device of homes and factories, it's suitable for the detection of liquefied gas, butane, propane, methane, smoke, etc.
PRODUCT FEATURES
It adopt the high quality dual-panel design with power indication and TTL signal output indication;
With DO switch signal (TTL) output and AO analog signal output;
The output signal of TTL is low. (When the output is low, the signal light can be directly connected with a single chip microcomputer or a relay module);
The voltage value will be higher if the concentration of analog output voltage is higher.
Good sensitivity to liquefied gas, natural gas, city gas and smoke;
There are four screw holes for easy positioning;
Has a long lifetime and reliable stability;
Rapid response and recovery characteristics.
ELECTRICAL PROPERTIES
Input voltage : DC5V Power consumption ( current ): 150mA;
DO output : TTL digital 0 and 1 ( 0.1 and 5V);
AO output :0.1-0.3 V ( relative to pollution ), the maximum concentration of the voltage is about 4V.

SPECIAL NOTE
After the sensor is powered, it needs around 20 seconds to warm up to make sure the measured date is stable. And the sensor heating is a normal phenomenon, because of the internal electric wire, but it's not normal if it is very hot.