Product Showcase: MQ Sensors

Smoke Sensor - MQ-2: www.sparkfun.com/products/17049
Dual Gas CO and CH4 Detection Sensor - MQ-9B: www.sparkfun.com/products/17050
Low Concentration Ozone Gas Sensor - MQ-131: www.sparkfun.com/products/17051
Hydrogen Sulfide Gas Sensor - MQ-136: www.sparkfun.com/products/17052
Ammonia Gas Sensor - MQ-137: www.sparkfun.com/products/17053
The MQ-2 Smoke Sensor can detect flammable gas in any range from 300 -10000ppm, and the heater uses 5V.
The MQ-9B sensor’s conductivity gets higher as the carbon monoxide and methane gas
concentrations rise. The heater uses an alternating voltage of 5V and 1.5V, depending on the gases. If you’re only testing Carbon Monoxide, the heater can be set to 1.5V. It has a sensing
range of 10-500ppm for methane.
The Low Concentration Ozone Gas Sensor is highly sensitive to ozone, also known as
trioxygen, and oxides like Chlorine & Nitrogen Dioxide. Its sensing range is 10-1000ppm, and the heater uses 6V. The load resistor for this sensor is a lot higher than the other sensors,
100/200k, and it’s incredibly sensitive. It measures in parts per billion rather than parts per
million.
MQ136 & MQ-137 both have heaters that use 5V. MQ-136 senses hydrogen sulfide, and MQ-137 senses Ammonia.

[@kcoRwobniaR]

More interesting that fact, that sensor have none-linear characteristic. And it depends on ambient humidity and temperature. So if you want collect accurate data you must collect and calculate complex variable: voltage, temperature, humidity. Output voltage depends logarithmic to temperature and humidity (Curves of dependence drawn in datasheet of particular MQ sensor). Just mapping max. min. voltage to PPM would not show exact concentration.

[@user-qc9iq8xb8s]

How are you calculating the voltage (sensor_volt) ? whay are you multiplying by 5 ? Could you please explain ..?

[@Qing-JolywoodSolar]

Very professional👍

[@shhashemi1387]

Great video. However it is not an advantage for an O3 to be sensitive to NO2 and Cl

[@brynleyevans8655]

The music in the background is annoying and distracts from the information.

[@Hash551]

What a lovely girl.