A
Anonymous
Mar 26, 2026
Rating: 4/5
Good value
Solid sensor for the price. Takes a while to warm up initially but performs as expected.
Description
MQ-135 Air Quality Sensor
Reviews
Attributes
| Brand | - |
| Category | Electronic Components / Maker DIY / Computer Hardware, Monitors & Peripherals |
| Origin | - |
| Operating Voltage | 5V DC |
| Detection Gases | NH3, NOx, Alcohol, Benzene, Smoke, CO2 |
| Output Type | Analog & Digital TTL |
| Heating Voltage | 5.0V ± 0.1V |
| Load Resistance | Adjustable Potentiometer |
| Heating Resistance | 33Ω ± 5% |
| Sensor Material | Tin Dioxide (SnO2) |
| Pin Interface | 4-Pin Header |
| PCB Dimensions | 32mm x 20mm x 10mm |
| Preheat Time | 24-48 Hours |
5 reviews
A
Anonymous
Mar 25, 2026
Rating: 4/5
Decent sensitivity
Detects smoke and alcohol well. Not precise for exact ppm measurement though.
A
Anonymous
Mar 13, 2026
Rating: 5/5
Great for Arduino projects
Works well with my Uno. Needed some calibration but readings are stable after warm-up.
A
Anonymous
Feb 11, 2026
Rating: 5/5
Easy to use
Plug and play with basic code. Helps monitor workshop air quality effectively.
A
Anonymous
Jan 24, 2026
Rating: 5/5
Reliable module
Been using it for a month in my ventilation project. No issues so far.
5 FAQ
Q: How long before it reads accurately?
A: We recommend 24-48 hours initial preheat for stability before calibration.
Q: What is the pinout layout?
A: VCC, GND, Digital Out, Analog Out from left to right when facing the component side.
Q: Does it come with calibration code?
A: We provide sample Arduino code in the documentation to help with setup.
Q: Can it detect carbon monoxide specifically?
A: It responds to CO among other gases but is not specific to CO alone.
Q: Is this 3.3V compatible?
A: The sensor heating requires 5V, but the signal output can be adapted for 3.3V logic.
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