MQ Series Gas Sensor

Hi guys, today we are going to talk about the gas sensor series you can also say that MQ gas sensor series. Detecting poisonous and pollution gases are always relevant to us, Gas sensor perform this operation, Some gas sensor is very expensive, luckily MQ gas sensor series provide you a cost-effective gas sensor which helps you detecting a particular gar excretion from a certain area,

What is Gas Sensor?

Gas sensors (also known as gas detectors) are electronic devices that detect and identify different types of gasses. They are commonly used to detect toxic or explosive gasses and measure gas concentration. Gas sensors are employed in factories and manufacturing facilities to identify gas leaks, and to detect smoke and carbon monoxide in homes.

Gas sensors vary widely in size (portable and fixed), range, and sensing ability. They are often part of a larger embedded system, such as security systems, and they are normally connected to an audible alarm or interface. Because gas sensors are constantly interacting with air and other gasses, they have to be calibrated more often than many other types of sensors. 

MQ2 is one of the commonly used gas sensors in MQ sensor series. It is a Metal Oxide Semiconductor (MOS) type Gas Sensor also known as Chemiresistors as the detection is based upon change of resistance of the sensing material when the Gas comes in contact with the material. Using a simple voltage divider network, concentrations of gas can be detected.

Here are some MQ series of gas sensors

• MQ-2 - Methane, Butane, LPG, smoke
• MQ-3 - Alcohol, Ethanol, smoke
• MQ-4 - Methane, CNG Gas
• MQ-5 - Natural gas, LPG
• MQ-6 - LPG, butane gas
• MQ-7 - Carbon Monoxide
• MQ-8 - Hydrogen Gas
• MQ-9 - Carbon Monoxide, flammable gasses
• MQ131 - Ozone
• MQ135 - Air Quality (CO, Ammonia, Benzene, Alcohol, smoke)
• MQ136 - Hydrogen Sulfide gas
• MQ137 - Ammonia
• MQ138 - Benzene, Toluene, Alcohol, Acetone, Propane, Formaldehyde gas, Hydrogen
• MQ214 - Methane, Natural gas

What is 1 ppm equal to?

When measuring gases like carbon dioxide, oxygen, or methane, the term concentration is used to describe the amount of gas by volume in the air. The 2 most common units of measurement are parts-per-million, and percent concentration.

Parts-per-million (abbreviated ppm) is the ratio of one gas to another. For example, 1,000ppm of CO means that if you could count a million gas molecules, 1,000 of them would be of carbon monoxide and 999,000 molecules would be some other gases.

Lets get on short discription and festures of each gas sensor.

MQ-2 Gas Sensor

Gas Sensor(MQ2) module is useful for gas leakage detection (home and industry). It is suitable for detecting H2, LPG, CH4, CO, Alcohol, Smoke, or Propane. Due to its high sensitivity and fast response time, a measurement can be taken as soon as possible. The sensitivity of the sensor can be adjusted by the potentiometer.

[caption id="attachment_9769" align="aligncenter" width="271"] MQ-2 Smoke LPG Butane Hydrogen Gas Sensor Detector Module[/caption]

Features

• Wide detecting scope
• Stable and long lifetime
• Fast response and High sensitivity

MQ-2 Sensor Datasheet

MQ-3 - Alcohol, Ethanol, Smoke

Gas Sensor(MQ3) module is useful for gas leakage detection (in home and industry). It is suitable for detecting Alcohol, Benzine, CH4, Hexane, LPG, CO. Due to its high sensitivity and fast response time, measurements can be taken as soon as possible. The sensitivity of the sensor can be adjusted by using the potentiometer.

[caption id="attachment_34589" align="aligncenter" width="361"] MQ-3 Alcohol Detector Gas Sensor Module[/caption]

Features

• High sensitivity to alcohol and small sensitivity to Benzine
• Stable and long life
• Fast response and High sensitivity

The output voltage from the Gas sensor increases when the concentration of gas increases. Sensitivity can be adjusted by varying the potentiometer. (Please note that the best preheat time for the sensor is above 24 hours.)  For detailed information about the MQ-3 sensor, please refer to the data-sheet provided.

MQ-3 Sensor Datasheet

MQ-4 - Methane, CNG Gas

As a natural gas sensor, the MQ-4 Natural Gas Sensor is a fast and reliable sensor with a high sensitivity to natural gas and methane, also good sensitivity to propane and butane. This natural gas sensor has a long life and low cost and is widely used for gas leak detection. At the same time, two LED lights are used in the project to display the gas concentration:

Greenlight: it means the natural gas concentration is below the critical value.

Red light: Alert! The natural gas concentration has exceeded the critical value.

[caption id="attachment_9774" align="aligncenter" width="271"] MQ-4 High Sensitivity Gas Methane (CNG) Detector Sensor Module[/caption]

Features

• Good sensitivity to Combustible gasin wide range.
• High sensitivity to CH₄, Natural gas.
• Small sensitivity to alcohol, smoke.
• Fast response Stable and long life.
• Simple drive circuit.

 MQ-4 sensor Datasheet

MQ-5 Sensor

The Gas Sensor(MQ5) module is useful for gas leakage detection (in home and industry). It is suitable for detecting H2, LPG, CH4, CO, Alcohol. Due to its high sensitivity and fast response time, measurements can be taken as soon as possible. The sensitivity of the sensor can be adjusted by using the potentiometer.

[caption id="attachment_65750" align="aligncenter" width="271"] MQ-5 Methane LPG Liquid Propane Gas Sensor Module[/caption]

Features

• Supply Voltage: 5V
• Detecting concentration:200-10000ppm LPG, LNG, Natural gas, Iso-butane
• Analog and Digital Output
• Digital Out is High or Low based on an adjustable preset threshold.

MQ-5 Sensor Datasheet

MQ-6 - LPG, Butane Gas

 This is a simple-to-use liquefied petroleum gas (LPG) sensor, MQ-6-LPG suitable for sensing LPG (composed of mostly propane and butane) concentrations in the air. The MQ-6 can detect gas concentrations anywhere from 200 to 10000ppm.

This sensor has high sensitivity and fast response time. The sensor’s output is an analog resistance. The drive circuit is very simple; all you need to do is power the heater coil with 5V, add a load resistance, and connect the output to an ADC.

[caption id="attachment_9803" align="aligncenter" width="288"] MQ-6 Liquefied Petroleum isobutane propane gas Sensor module[/caption]

Features

• High Sensitivity to LPG, iso-butane, propane
• Small sensitivity to alcohol, smoke
• Detection Range: 100 - 10,000 ppm iso-butane propane
• Fast Response Time: <10s
• Simple drive circuit
• Heater Voltage: 5.0V

MQ-6 Sensor Datasheet

MQ-7 - Carbon Monoxide

Sensitive material of the MQ-7 gas sensor is SnO2, which with lower conductivity in clean air. It makes 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 the high temperature (heated by 5.0V), it cleans the other gases adsorbed under low temperatures. Please use simple electro-circuit, Convert change of conductivity to correspond output signal of gas concentration. MQ-7 gas sensor has a high sensitivity to Carbon Monoxide. The sensor could be used to detect different gases contains CO, it is at low cost and suitable for different applications.

[caption id="attachment_44012" align="aligncenter" width="299"] MQ-7 CO Carbon Monoxide Coal Gas Sensor Module[/caption]

Features

• Good sensitivity to Combustible gas in wide range
• High sensitivity to Natural gas
• Long life and low cost
• Simple drive circuit

MQ-7 Sensor Datasheet

MQ-8 - Hydrogen Gas

 Hydrogen Gas Sensor for measuring the concentration of Hydrogen (H2) in the air. Suitable for measuring concentrations from 100 to 10,000 ppm. Easy to implement heater drive and measuring circuit. This sensor is designed for long life and stable output. Our MQ-8 Hydrogen Gas Sensor is ideal for use in a Gas Leakage Circuit for detecting gas leaks.

[caption id="attachment_44023" align="aligncenter" width="290"] MQ-8 gas sensor[/caption]

Features

• High Sensitivity (MQ-8 Sensor)
• Stable and Long Life
• Detection Range: 100 - 10,000 ppm H2 (Hydrogen)
• Heater Voltage: 5.0V
• Dimensions: 18mm Diameter, 17mm High excluding pins, Pins - 6mm High

MQ-8 Sensor Datasheet

MQ-9 - Carbon Monoxide, Flammable Gases

The MQ-9 Analog Gas Sensor has a high sensitivity to Carbon Monoxide, Methane, and LPG. The sensor that can be used to detect different gases containing the MQ-9 gas sensor is SnO2, which has lower conductivity in clean air. It makes detection by cycling high and low temperature and detects CO when low temperature (heated by 1.5V). The sensor’s conductivity is higher along with the gas concentration rising. When temperature rises (heated by 5.0V), it detects Methane, Propane, combustible gas, etc and cleans the other gases as it adsorbed under low temperature. MQ-9 usually applied in domestic gas leakage detector, industrial gas detector, portable gas detector, etc. 

[caption id="attachment_43974" align="aligncenter" width="289"] MQ-9 Carbon Monoxide, Methane and LPG Gas Sensor Module[/caption]

Features

• Power supply: 5V
• Concentration: Good sensitivity to CO/Combustible gas
• High sensitivity to Methane, Propane, and CO
• Long life and low cost
• Standard Encapsulation: Bakelite
• Detection Gas: CO and combustible gas
• Loop Voltage: ≤10V DC
• Load Resistance: Adjustable
• Heater Resistance: 31Ω±3Ω(Room Tem.)
• Heater consumption: ≤350mW

MQ-9 Sensor Datasheet

MQ131 - Ozone

Sensitive material of MQ131 gas sensor is SnO2, which with lower conductivity in clean air. When Ozone gas exists. The sensor’s conductivity is higher along with the gas concentration rising. Please use simple electro circuit, Convert change of conductivity to correspond output signal of gas concentration. MQ131 gas sensor has a high sensitivity to Ozone, also sensitive to CL2, NO2, etc.

[caption id="attachment_752160" align="aligncenter" width="290"] MQ-131 gas sensor[/caption]

Features

• Good sensitivity to Ozone in a wide range
• High sensitivity to Ozone
• Long life and low cost
• Simple drive circuit

MQ-131 Sensor Datasheet

MQ135 - Air Quality (CO, Ammonia, Benzene, Alcohol, Smoke)

Air quality sensor for detecting a wide range of gases, including NH3, NOx, alcohol, benzene, smoke, and CO2. Ideal for use in office or factory. MQ135 gas sensor has a high sensitivity to Ammonia, Sulfide, and Benze steam, also sensitive to smoke and other harmful gases. It is at low cost and particularly suitable for Air quality monitoring applications.

[caption id="attachment_74151" align="aligncenter" width="291"] MQ 135 Air Quality Detector Sensor[/caption]

Features

• High Sensitivity
• High sensitivity to Ammonia, Sulfide, and Benze
• Stable and Long Life
• Detection Range: 10 - 300 ppm NH3, 10 - 1000 ppm Benzene, 10 - 300 Alcohol
• Heater Voltage: 5.0V
• Dimensions: 18mm Diameter, 17mm High excluding pins, Pins - 6mm High
• Long life and low cost

MQ-135 Sensor Datasheet

MQ136 - Hydrogen Sulfide Gas

 Sensitive material of MQ136 gas sensor is SnO2, which with lower conductivity in clean air. When the target Hydrogen sulfide gas exists, the sensor’s conductivity is higher along with the Hydrogen sulfide concentration rising. Please use a simple electric circuit, Convert change of conductivity to correspond output signal of gas concentration.
MQ136 gas sensor has a high sensitivity to Hydrogen sulfide, Low sensitivity for other combustible gas. It is at a low cost and suitable for different applications.

Character:

1. Good sensitivity to hydrogen sulphide
2. Long life and low cost
3. Simple drive circuit

[caption id="attachment_752162" align="aligncenter" width="392"] MQ-136 gas sensor[/caption]

Features

• Sensitive material of MQ136 gas sensor is SnO2, which with lower conductivity in clean air. When the target Hydrogen sulfide gas exists, the sensor’s conductivity is higher along with the Hydrogen sulfide concentration rising. Please use a simple electric circuit, Convert change of conductivity to correspond output signal of gas concentration.
• MQ136 gas sensor has a high sensitivity to Hydrogen sulfide, Low sensitivity for other combustible gas. It is at a low cost and suitable for different applications. Character:
• Good sensitivity to Hydrogen sulfide
• Long life and low cost
• Simple drive circuit

MQ-136 Sensor Datasheet

MQ137 – Ammonia

The MQ-137 Gas sensor can detect or measure gasses like Ammonia (NH3) and Carbon Mono-oxide (CO). The module version of this sensor comes with a Digital Pin which makes this sensor operate even without a microcontroller and that comes in handy when you are only trying to detect one particular gas. When it comes to measuring the gas in ppm the analog pin has to be used, the analog pin is also TTL driven and works on 5V and hence can be used with most common microcontrollers.

[caption id="attachment_752163" align="aligncenter" width="298"] MQ-137 gas sensor[/caption]

Features

• Operating Voltage is +5V
• Can be used to Measure Ammonia, Carbon monoxide
• Analog output voltage: 0V to 5V
• Digital Output Voltage: 0V or 5V (TTL Logic)
• Preheat duration over 24 hours
• Can be used as a digital or analog sensor
• The Sensitivity of Digital pin can be varied using the potentiometer

MQ-137 Sensor Datasheet

MQ138 - Benzene, Toluene, Alcohol, Acetone, Propane, Formaldehyde Gas, Hydrogen

Sensitive material of MQ138 gas sensor is SnO2, which with lower conductivity in clean air. Whenthe target Organic Steam exists, The sensor’s conductivity is higher along with the gasconcentration rising. Please use simple electro circuit, Convert change of conductivity to correspond output signal of gas concentration.

MQ138 gas sensor has a high sensitivity to Toluene, Acetone, Ethanol, and Formaldehyde, also to other organic steam. The sensor could be used to detect different organic steam, it is with low cost and suitable for different application

[caption id="attachment_752165" align="aligncenter" width="301"] MQ-138 gas sensor[/caption]

Features

• Module with MQ138 gas sensor and circuitry to enable easy plug and use, just connect power and the module is ready to interface with microcontroller.
• Working voltage: DC 5V
• Comes with power and digital signal LED indicator
• 2-way signal output (analog output, and TTL-level output)
• TTL output valid signal is low; (low output signal light, which can be accessed microcontroller IO port)
• Analog output increases with the concentration, the higher the voltage the higher the concentration Aldehydes, alcohols, ketones, aromatic compounds with high sensitivity
• With a long life and reliable stability
• Fast response characteristics
• With mounting holes for easy permanent installation
• Main chip: LM393, formaldehyde-sensing probe

MQ-138 Sensor Datasheet

MQ214 - Methane, Natural Gas

MQ - 214 is a Methane (CH4) gas sensor detects the concentrations of methane in the air and outputs its reading as an analog voltage. precaution The gasses detected by these gas sensors can be deadly in high concentrations. Always be careful to perform gas tests in well-ventilated areas.

[caption id="attachment_752166" align="aligncenter" width="301"] mq-214 gas sensor[/caption]

Features

• Product Type: Semiconductor gas sensor
• Standard package: Metal High sensitivity Fast response and recovery Long life, low power consumption costs Simple drive circuit can be
• Detection gas: Methane, natural gas, liquefied petroleum gas, hydrogen.
• Detectable concentration: 500-10000ppm,LPG and propane; 1000-20000ppm methane; 500-10000ppm hydrogen.
• Applications: Family with combustible gas leak alarm; Industrial combustible gas leak alarm; Suitable for methane, natural gas, liquefied petroleum gas, hydrogen detection.

MQ-214 Sensor Datasheet

 So Guys, this is an overview for gas sensors, Hope this will help you to find a sensor for a perticular gas you want to monitor, plus I have also attached the datasheet of respective gas sensor, you can download it from the link mentioned in respective sensor.

Next time when you will gonna make some cool projects regarding gas monitoring, gas detection, gas control,I hope this article will definetly help you.

Write down the comment if you have any minor doubt related to gas sensors. Stay tuned!

 

Tags : gas sensor , mq-sseries gas sensors