Product Introduction
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Organic Vapor Sensor MQ138 Product Description
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The gas sensing material used in the MQ138 gas sensor is tin dioxide (SnO2) with low conductivity in clean air. When organic vapors are present in the environment, the sensor's conductivity increases with the concentration of organic vapors in the air. A simple circuit can convert the change in conductivity into an output signal corresponding to the gas concentration.
The MQ138 gas sensor has high sensitivity to toluene, acetone, ethanol, and formaldehyde, and is also ideal for monitoring hydrogen and other organic vapors. This sensor can detect a variety of organic vapors and is a low-cost sensor suitable for multiple applications.
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Organic Vapor Sensor MQ138Sensor Features
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Good sensitivity to organic vapors over a wide concentration range
High sensitivity to toluene, acetone, and ethanol
Long life, low cost
Simple drive circuit required
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Organic Vapor Sensor MQ138Main Applications
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Household gas concentration alarms
Industrial organic vapor alarms
Portable gas detectors
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Organic Vapor Sensor MQ138Technical Specifications
| Model |
MQ138 |
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| Product Type |
Semiconductor gas sensing element |
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| Standard Package |
Bakelite (black bakelite) |
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| Detection Gas |
Toluene, acetone, ethanol, hydrogen |
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| Detection Concentration |
5-500ppm |
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| Standard Circuit Conditions |
Loop Voltage |
Vc |
≤24V DC |
| Heating Voltage |
VH |
5.0V±0.2V ACorDC |
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| Load Resistance |
RL |
Adjustable |
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| Gas Sensing Element Characteristics under Standard Test Conditions |
Heating Resistance |
RH |
31Ω±3Ω (room temperature) |
| Heating Power Consumption |
PH |
≤900mW |
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| Surface Resistance of Sensing Body |
Rs |
2KΩ-20KΩ (in 50ppm toluene) |
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| Sensitivity |
S |
Rs(in air)/Rs(in 50ppm toluene) ≥ 3 |
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| Concentration Slope |
α | ≤0.6(R100ppm/R50ppmToluene) |
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| Standard Test Conditions |
Temperature, Humidity |
20℃±2℃；65%±5%RH |
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| Standard Test Circuit |
Vc:5.0V±0.1V； VH: 5.0V±0.1V |
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| Preheating Time |
No less than 48 hours |
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