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Seeed Gas Sensor Selection Guide

11.12.2019

Gas sensor is a device which can detect the presence of various toxic and combustible gases present in the environment.

 

Operating Principle

The interaction between the test gas and the sensing surface can be detected by the measurements of change in resistance, capacitance, work function, mass, optical characteristics etc. Below table is from Source.

Class of gas sensors Operating principle
Electrochemical Changes in current, voltage, capacitance/impedance: 1. Voltammetry (including amperometry) 2. Potentiometry 3. Chemically sensitized field-effect transistor 4. Potentiometry with solid electrolytes for gas sensing
Electrical Metal oxide conductivity Organic conductivity Electrolytic conductivity Heterojunction conductivity (Schottky diode, FET, MOS) Work function Electric permittivity (capacitance)
Mass sensitive Changes in the weight, amplitude, phase or frequency, size, shape, or position: 1. Quartz crystal microbalance 2. Surface acoustic wave propagation 3. Cantilever
Magnetic Changes of paramagnetic gas properties
Optical devices Changes in light intensity, color, or emission spectra: 1. Absorbance 2. Reflectance 3. Luminescence 4. Refractive index 5. Optothermal effect 6. Light scattering (Raman scattering, plasmon resonance)
Thermometric (calorimetric) Heat effects of a specific chemical reaction. Changes in temperature, heat flow, heat content: 1. Thermoelectric 2. Pyroelectric 3. Catalytic bead (pellistors) 4. Thermal conductivity

Table 1.The classification of gas sensors suggested in 1991 by Analytical Chemistry Division of IUPAC

 

Field of Applicaitons

There are a numerous use of these gas sensors. Particularly, using these gas sensors human beings can be saved from potential dangers. Hence the gas sensors play important roles in various sectors, which include industry, medical, environmental applications, and domestic applications for monitoring toxic and flammable gases. Below table is from Source.

Field of application Function Examples of detected gases
Environment Monitoring toxic gases present in the atmosphere, due to industrial emissions (weather stations, pollutionmonitoring) CO, CH4, humidity, CO2, O3, VOCs, SOx
Safety at work Control of indoor air quality; monitoring toxic gases in a working environment, for instance in a factory where dangerous chemicals are used Toxic gases, combustible gases, O2
Domestic safety/household application Detection of poisonous gases or smoke in households, due to accidents such as fires and explosions; intelligent refrigera­tor or oven; fire alarm; natural gas heating; leak detection; air quality control; air purifiers; cooking control CO, humidity, CO2, VOCs
Safety in car Car ventilation control; gasoline vapor detection; alcohol breath tests CO, LPG, VOCs, CH4
Public security Control of indoor air quality, detection of substances dangerous for the safety of the general public Toxic gases, combustible gases, flammable gases, explosives, O2
Medical/clinical Diagnostics(breath analysis, disease detection); point-of-care patient monitoring; drug monitoring; artificial organs and prostheses; new drug discovery O2, NH, NOx, CO2, H2S, H2, CL2, anesthesia gases
Agriculture Plant/animal diagnostics; soil and water testing; meat/poultry inspect ion; waste/sewage monitoring Amines, humidity, CO
Food quality control Detection of particular molecules, which are formed when food starts to rot and it is no longer good for consumption Humidity, CO2
Utilities/automotive/power plants Control of the concentration of the gases in the engine and gas boiler, to guarantee the highest possible efficiency of the combustion process. The same concept can also be applied to power plants, as the energy is generated by combustion O2, CO, HCs, NOx, SOx, CO2, H2, HCs
Industry: Petrochemical Steel/Water treatment/Semiconductor Process monitoring and control; quality control; workplace monitoring; waste stream monitoring; leakage alarm HCs, conventional pollutants, O2, H2, O3, CO2, CL2, CH4,H2S
Defense/military Detection of chemical, biological, and toxin warfare agents; treaty verification Agents, explosives, propellants
Aerospace Monitoring of oxygen and toxic and flammable gases in the environ­ment atmosphere H2, O2, CO3, humidity
Traffic/tunnels/car parks City traffic control and management; air quality monitoring in tunnels or underground parking garages  
 
Table 2.Some examples of gas sensor applications

 

Seeed Gas Sensor

Order
Name
Target Gas
Class of gas sensors
Field of application
Sensor
Detecting Range
Accuracy
Operate voltage
Interface
Grove - Air Quality Sensor v1.33
Alcohol, Smoke
Electrochemical
Environment
MP503
10-1000ppm(Alcohol)
NA
3.3V 5V
Analog
Grove - Alcohol Sensor
Alcohol
Electrochemical
Safety in car Public security
MQ303A
20-1000ppm Alcohol
NA
5V
Analog
Grove - CO2 Sensor
CO2
Electrochemical
Environment Agriculture
MH-Z16
0÷5000ppm
±(50ppm +5%)
5V
UART
Grove - CO2 & Temperature & Humidity Sensor (SCD30)
CO2
Оптични устройства
Environment Agriculture
SCD30
0÷40000ppm
±(30 ppm + 3%)
3.3V 5V
I2C
Grove - VOC and eCO2 Gas Sensor (SGP30)
VOC,CO2
Electrical
Environment Agriculture
SGP30
VOC: 0÷60000ppb
CO2: 400÷60000ppm
VOC: (0÷2008ppb/1ppb,
2008÷11110ppb/6ppb,
11110÷60000ppb/32ppb)
CO2: (400÷1479ppm/1ppm,
1479÷5144ppm/3ppm,
5144÷17597ppm/9ppm,
7597÷60000ppm/31ppm)
3.3V 5V
I2C
Grove - Gas Sensor(MQ2)
LPG, i-butane, propane, methane, alcohol, Hydrogen, smoke
Electrochemical
Domestic safety/household application Safety at work
MQ2
LPG and propane: 200ppm-5000ppm Butane: 300ppm-5000ppm
Methane: 5000ppm-20000ppm
H2: 300ppm-5000ppm Alcohol:100ppm-2000ppm
NA
5V
Analog
Grove - Gas Sensor(MQ3)
High sensitivity to alcohol and small sensitivity to Benzine
Electrochemical
Safety in car Public security
MQ3
Alcohol: 0.05-10mg/L
NA
5V
Analog
Grove - Gas Sensor(MQ5)
High sensitivity to LPG, natural gas, town gas and Small sensitivity to alcohol, smoke
Electrochemical
Industry: Petrochemical Steel/Water treatment/ Semiconductor Utilities/automotive/power plants
MQ5
200÷10000ppm
NA
5V
Analog
Grove - Gas Sensor(MQ9)
High sensitivity to carbon monoxide and CH4,LPG
Electrochemical
Safety in car Industry: Petrochemical Steel/Water treatment/Semiconductor Utilities/automotive/power plants Domestic safety/household application
MQ9
Carbon monoxide: 20-2000ppm CH4: 500-10000ppm LPG: 500-10000ppm
NA
5V
Analog
Grove - Gas Sensor(O2)
O2
Electrochemical
Safety in car Industry: Petrochemical Steel/Water treatment/Semiconductor Utilities/automotive/power plants Domestic safety/household application
ME2-O2-Ф20
0÷25%Vol
NA
3.3V 5V
Analog
Grove - HCHO Sensor
Toluene, methanal, benzene, alcohol, acetone
Electrochemical
Environment
WSP2110
1÷50ppm
NA
3.3V 5V
Analog
Grove - Temperature, Humidity, Pressure and Gas Sensor (BME680)
IAQ
Electrical
Environment Domestic safety/household application
BME680
0÷500
NA
3.3V 5V
I2C

 Table 3.Seeed Gas Sensor Category

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